Middle School Science Quiz: Variables Affecting Motion

20 questions · exam conditions

0:00

Variables Affecting MotionQuestion 1 of 20

A student investigates: How does mass affect how fast a cart rolls down a ramp? The student changes only the mass by adding washers. Which variable should be placed on the x-axis of a graph?

Independent variable is usually on the x-axis. Dependent variable is usually on the y-axis.

Speed at the bottom of the ramp

Mass of the cart

Ramp height

Wheel type

← Back to quizzes

Middle School Science Quiz

Middle School Science Quiz: Variables Affecting Motion

Practice Variables Affecting Motion in Middle School Science with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Variables Affecting Motion, giving you a quick way to practice the rules, question types, and explanations that matter most for Middle School Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A student investigates: How does mass affect how fast a cart rolls down a ramp? The student changes only the mass by adding washers. Which variable should be placed on the x-axis of a graph?

Independent variable is usually on the x-axis. Dependent variable is usually on the y-axis.

Speed at the bottom of the ramp
Mass of the cart (correct answer)
Ramp height
Wheel type

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does mass affect how fast a cart rolls down a ramp?": The independent variable is mass of the cart (changed by adding washers) because that's what you deliberately change to test the effect; the dependent variable is speed at the bottom of the ramp because that's what you measure to see how mass affects it; the controlled variables include ramp height and wheel type (kept the same)—keeping these constant ensures that any speed differences are due to mass changes, not other factors. Choice B is correct because it properly identifies the independent variable as what you change to test the question, and independent variables are usually placed on the x-axis of a graph (mass, varied by adding washers). Choice A is wrong because it confuses variable types: it suggests putting the dependent variable (speed at the bottom, what you measure) on the x-axis, but dependent variables go on the y-axis. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 2

A student investigates: How does the mass of a cart affect how fast it rolls down a ramp? The student will add different masses to the same cart and release it from the same starting point on the ramp each time. Which variable is the independent variable in this investigation?

The ramp height (starting position)
The mass added to the cart (correct answer)
The speed of the cart at the bottom of the ramp
The surface texture of the ramp

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the mass of a cart affect how fast it rolls down a ramp?": The independent variable is the mass added to the cart because that's what you deliberately change to test the effect (you'd test with different masses: perhaps 1 kg cart, then add weights to make 2 kg cart, then 3 kg cart—you control the mass values). The dependent variable is the speed of the cart at the bottom of the ramp because that's what you measure to see how mass affects it (use a stopwatch and meter stick to calculate speed at the bottom of the ramp for each mass—speed depends on mass, changes in response to changing mass). The controlled variables include ramp height (keep same angle for all trials), surface texture of the ramp (same ramp material for all), starting position (release from same spot every time)—keeping these constant ensures that any speed differences observed are due to mass changes, not other factors. Choice B is correct because it properly identifies the independent variable as what you change to test the question. Choice A is wrong because it confuses variable types: calls the controlled variable (ramp height, which should be kept the same) the independent variable, suggesting changing what should be constant (would ruin fair test). Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 3

A student investigates: How does surface type affect the distance a toy car rolls? The student tests on carpet, tile, and sandpaper. Which variable is the controlled variable (constant) that should be kept the same?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

Surface type
Distance traveled
The starting push force (correct answer)
The results recorded in the data table

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does surface type affect the distance a toy car rolls?": The independent variable is surface type (carpet, tile, sandpaper) because that's what you deliberately change to test the effect; the dependent variable is distance traveled because that's what you measure to see how surface affects it; the controlled variables include the starting push force (kept the same for fair test)—keeping this constant ensures that any distance differences are due to surface changes, not push variations. Choice C is correct because it accurately lists a controlled variable as a factor kept constant for fair test (the starting push force, unchanged to isolate surface effect). Choice A is wrong because it lists the independent variable (surface type, what you change) as controlled, suggesting keeping constant what should be changed, which would ruin the fair test. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 4

A student investigates: How does the starting height of a ball on a ramp affect its speed at the bottom? Which choice correctly matches each variable to its role?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

Independent: speed at bottom; Dependent: starting height; Controlled: ball type
Independent: starting height; Dependent: speed at bottom; Controlled: same ball and same ramp surface (correct answer)
Independent: ramp surface; Dependent: starting height; Controlled: speed at bottom
Independent: same ball; Dependent: ramp surface; Controlled: starting height

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the starting height of a ball on a ramp affect its speed at the bottom?": The independent variable is starting height because that's what you deliberately change to test the effect; the dependent variable is speed at the bottom because that's what you measure to see how height affects it; the controlled variables include same ball (constant mass) and same ramp surface—keeping these constant ensures that any speed differences are due to height changes, not other factors. Choice B is correct because it correctly matches variable types to their roles in this specific investigation (independent as starting height changed, dependent as speed measured, controlled as same ball and ramp surface kept constant). Choice A is wrong because it confuses variable types: it calls the independent variable dependent and vice versa (speed as independent, height as dependent), mixing up what you change vs what you measure. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 5

A student investigates: How does the mass of a cart affect how fast it rolls down a ramp? The student adds different numbers of washers to the same cart, releases it from the same starting line, and measures the cart's speed at the bottom. Which variable is the independent variable in this investigation?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

The ramp height and starting position
The cart's speed at the bottom of the ramp
The mass of the cart (number of washers added) (correct answer)
The time of day the test is done

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the mass of a cart affect how fast it rolls down a ramp?": The independent variable is the mass of the cart (number of washers added) because that's what you deliberately change to test the effect (you'd test with different masses: perhaps adding 0, 2, or 4 washers—you control the mass values); the dependent variable is the cart's speed at the bottom of the ramp because that's what you measure to see how mass affects it (use a stopwatch and meter stick to calculate speed for each mass—speed depends on mass, changes in response to changing mass); the controlled variables include ramp height (keep same for all trials), surface (same ramp material), and starting position (release from same line every time)—keeping these constant ensures that any speed differences observed are due to mass changes, not other factors. Choice C is correct because it properly identifies the independent variable as what you change to test the question (the mass of the cart, varied by adding washers). Choice A is wrong because it confuses variable types: it lists controlled variables (ramp height and starting position, which should be kept the same) as if they were the independent variable, mixing up what you keep constant vs what you change. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 6

A student investigates: How does surface type affect how far a toy car rolls? The student uses the same toy car and the same starting push each time, but tests it on tile, wood, and carpet. The student measures the distance the car travels. Which set of variables should be controlled (kept the same) to make the test fair?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

Surface type and distance traveled
Toy car mass, the starting push force, and the starting position (correct answer)
Distance traveled and time to stop
Surface type and the starting push force

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does surface type affect how far a toy car rolls?": The independent variable is surface type (tile, wood, carpet) because that's what you deliberately change to test the effect; the dependent variable is distance traveled because that's what you measure to see how surface affects it; the controlled variables include toy car mass (same car), the starting push force (same each time), and starting position (same spot)—keeping these constant ensures that any distance differences are due to surface changes, not other factors. Choice B is correct because it accurately lists controlled variables as factors kept constant for fair test (toy car mass, starting push force, and starting position, all unchanged to isolate surface effect). Choice A is wrong because it lists the independent variable (surface type, what you change) and dependent variable (distance traveled, what you measure) as controlled, suggesting keeping constant what should be changed or measured, which would ruin the fair test. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 7

A student investigates: How does the amount of force applied to a cart affect its acceleration? The student uses the same cart on the same surface but pulls it using a rubber band stretched to 2 cm, 4 cm, and 6 cm. The student then measures the cart's acceleration. Which statement best explains why the surface should be kept the same?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

So the acceleration changes only because of the force, not because friction changed (correct answer)
So the independent variable changes automatically
So the cart's mass increases each trial
So the dependent variable (acceleration) stays the same each trial

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the amount of force applied to a cart affect its acceleration?": The independent variable is the amount of force (rubber band stretched to 2 cm, 4 cm, 6 cm) because that's what you deliberately change to test the effect; the dependent variable is the cart's acceleration because that's what you measure to see how force affects it; the controlled variables include the surface (kept the same) and cart (same one)—keeping these constant ensures that any acceleration differences are due to force changes, not other factors like friction variations. Choice A is correct because it explains why a controlled variable (surface kept the same) is important for a fair test, ensuring acceleration changes only because of the force, not because friction changed. Choice D is wrong because it incorrectly states the purpose of controlling variables: it claims the dependent variable (acceleration) should stay the same each trial, but the dependent should change in response to the independent for the investigation to show effects. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 8

A student wants to test: How does the amount of force affect the speed of a cart on a flat surface? Which plan is the best example of a fair test?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

Use the same cart and surface, change the push strength, and measure the cart's speed each time (correct answer)
Change the push strength and also change to a different cart each time, then measure distance traveled
Keep the push strength the same, change the cart's mass, and measure speed
Change the surface type and the push strength at the same time, then measure speed

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the amount of force affect the speed of a cart on a flat surface?": The independent variable is the amount of force (push strength) because that's what you deliberately change to test the effect; the dependent variable is the cart's speed because that's what you measure to see how force affects it; the controlled variables include the cart (same one) and surface (same flat surface)—keeping these constant ensures that any speed differences are due to force changes, not other factors. Choice A is correct because it correctly matches variable types to their roles in this specific investigation (changes only push strength as independent, measures speed as dependent, keeps cart and surface the same as controlled for a fair test). Choice B is wrong because it suggests changing multiple variables simultaneously (push strength and cart each time), which would not be a fair test because you couldn't tell which variable caused the observed effect in distance traveled. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 9

A student investigates: How does the starting height of a ball on a ramp affect its speed at the bottom? The student changes the release height (low, medium, high), uses the same ball, and measures the speed at the bottom with a stopwatch and a marked distance. Which variable is the independent variable?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

The speed of the ball at the bottom
The ball's mass (same ball used)
The starting height on the ramp (correct answer)
The ramp surface (kept the same)

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the starting height of a ball on a ramp affect its speed at the bottom?": The independent variable is the starting height on the ramp (low, medium, high) because that's what you deliberately change to test the effect; the dependent variable is the speed of the ball at the bottom because that's what you measure to see how height affects it (using stopwatch and marked distance); the controlled variables include the ball's mass (same ball) and ramp surface (kept the same)—keeping these constant ensures that any speed differences are due to height changes, not other factors. Choice C is correct because it properly identifies the independent variable as what you change to test the question (the starting height on the ramp, deliberately varied). Choice A is wrong because it confuses variable types: it calls the dependent variable (speed at the bottom, what you measure) the independent variable, mixing up what you measure vs what you change. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 10

A student investigates: How does mass affect a cart's acceleration when the same force is applied? The student attaches a rubber band to pull the cart with the same stretch each time, but adds 0, 1, or 2 identical masses to the cart. The student measures acceleration by timing how long it takes to travel 1 meter. Which variable is the dependent variable?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

How much the rubber band is stretched
The cart's acceleration (found from the motion data) (correct answer)
The mass added to the cart
The type of floor surface

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does mass affect a cart's acceleration when the same force is applied?": The independent variable is the mass added to the cart (0, 1, or 2 masses) because that's what you deliberately change to test the effect; the dependent variable is the cart's acceleration (found from the motion data, like timing to travel 1 meter) because that's what you measure to see how mass affects it; the controlled variables include how much the rubber band is stretched (same stretch for same force) and the type of floor surface (kept the same)—keeping these constant ensures that any acceleration differences are due to mass changes, not other factors. Choice B is correct because it correctly identifies the dependent variable as what you measure to observe effects (the cart's acceleration, responding to changes in mass). Choice A is wrong because it confuses variable types: it calls a controlled variable (how much the rubber band is stretched, kept the same for constant force) the dependent variable, mixing up what you keep constant vs what you measure. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 11

A student investigates: How does the amount of force applied to a cart affect its acceleration? They plan to test three different forces. Which statement best explains why force is the independent variable in this investigation?

Force is independent because it is what the student changes on purpose to see how acceleration responds (correct answer)
Force is independent because it is what the student measures at the end of each trial
Force is independent because it should be kept the same so the test is fair
Force is independent because acceleration causes the force to increase

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the amount of force applied to a cart affect its acceleration?": The independent variable is the amount of force because that's what you deliberately change to test the effect (three different forces—you control the force). The dependent variable is acceleration because that's what you measure to see how force affects it (acceleration responds to force changes). The controlled variables include cart mass, surface—keeping these constant ensures fair test. Choice A is correct because it properly identifies the independent variable as what you change to test the question. Choice B is wrong because it confuses variable types: suggests the independent variable is what you measure, mixing up roles (independent is changed, not measured). Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 5 N, 10 N, 15 N), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like acceleration with sensor), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does mass affect acceleration?"—independent: mass (1 kg, 2 kg, 3 kg), dependent: acceleration (measure), controlled: force (same), surface (same)—by changing only mass and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma, acceleration inversely proportional to mass), which is the goal of variable-controlled experimentation.

Question 12

A student investigates: How does the amount of force used to push a cart on a flat surface affect its motion? The student keeps the same cart on the same floor and gives it a weak, medium, and strong push. The student records how far the cart travels before stopping. Which variable is the dependent variable?

Independent: [what you change] Dependent: [what you measure] Controlled: [what you keep the same]

How far the cart travels before stopping (correct answer)
The surface type (floor material)
The mass of the cart
The strength of the push (force applied)

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the amount of force used to push a cart on a flat surface affect its motion?": The independent variable is the strength of the push (force applied) because that's what you deliberately change to test the effect (weak, medium, strong—you control the force levels); the dependent variable is how far the cart travels before stopping because that's what you measure to see how force affects it (record distance for each push—distance depends on force, changes in response); the controlled variables include the mass of the cart (keep same cart) and surface type (same floor material)—keeping these constant ensures that any distance differences are due to force changes, not other factors. Choice A is correct because it correctly identifies the dependent variable as what you measure to observe effects (how far the cart travels before stopping, responding to changes in force). Choice D is wrong because it confuses variable types: it calls the independent variable (strength of the push, what you change) the dependent variable, mixing up what you change vs what you measure. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch and meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (use spring scale to apply 5 N, 10 N, 15 N forces), dependent: acceleration (measure using motion sensor or calculating from distance and time), controlled: cart mass (same cart all trials), surface (same table), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma predicts acceleration proportional to force), which is the goal of variable-controlled experimentation.

Question 13

A student investigates: How does the amount of force used to push a cart on a flat surface affect its motion? The student uses the same cart on the same floor, but gives it a weak push, a medium push, and a strong push. What is the dependent variable the student should measure to answer the question?

The speed of the cart after the push (or the distance it travels) (correct answer)
The mass of the cart
The type of floor surface (tile vs carpet)
The strength of the push (force applied)

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does the amount of force used to push a cart on a flat surface affect its motion?": The independent variable is the strength of the push (force applied) because that's what you deliberately change to test the effect (weak push, medium push, strong push—you control the force amount). The dependent variable is the speed of the cart after the push (or the distance it travels) because that's what you measure to see how force affects it (use a stopwatch and meter stick to calculate speed or distance—motion depends on force, changes in response to changing force). The controlled variables include mass of the cart (keep same cart for all trials), type of floor surface (same floor for all), starting position (begin from same location)—keeping these constant ensures that any motion differences observed are due to force changes, not other factors. Choice A is correct because it correctly identifies the dependent variable as what you measure to observe effects. Choice D is wrong because it confuses variable types: calls the independent variable (strength of push, which you change) the dependent variable, mixing up what you change vs what you measure. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like weak, medium, strong), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like distance with meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does mass affect speed?"—independent: mass (1 kg, 2 kg, 3 kg), dependent: speed (measure with stopwatch), controlled: ramp height (same), surface (same), starting position (same)—by changing only mass and measuring only speed while controlling everything else, you can determine the relationship, which is the goal of variable-controlled experimentation.

Question 14

A student wants to test: How does mass affect acceleration when the same force is applied? They plan to pull a cart with a rubber band stretched the same amount each time (same pulling force). What should the student change on purpose (the independent variable)?

How much the rubber band is stretched
The total mass of the cart (add weights to the cart) (correct answer)
The cart's acceleration (measure this)
The type of cart wheels

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does mass affect acceleration when the same force is applied?": The independent variable is the total mass of the cart (add weights to the cart) because that's what you deliberately change to test the effect (different masses: add weights to vary—you control the mass). The dependent variable is the cart's acceleration because that's what you measure to see how mass affects it (measure acceleration using tools—acceleration depends on mass, changes in response). The controlled variables include how much the rubber band is stretched (same force each time), type of cart wheels (same cart)—keeping these constant ensures that any acceleration differences are due to mass changes, not other factors. Choice B is correct because it properly identifies the independent variable as what you change to test the question. Choice A is wrong because it lists controlled variable as independent, suggesting changing what should be kept constant (rubber band stretch should be same for fair test). Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like 1 kg, 2 kg, 3 kg), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like acceleration with sensor), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (5 N, 10 N, 15 N), dependent: acceleration (measure), controlled: mass (same), wheels (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma), which is the goal of variable-controlled experimentation.

Question 15

A student investigates: How does starting height on a ramp affect the speed of a ball at the bottom? The student releases the same ball from three different heights on the same ramp. Which variable is the dependent variable?

The height where the ball starts on the ramp
The ramp surface material
The speed of the ball at the bottom of the ramp (correct answer)
The mass of the ball

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does starting height on a ramp affect the speed of a ball at the bottom?": The independent variable is the height where the ball starts on the ramp because that's what you deliberately change to test the effect (three different heights—you control the height values). The dependent variable is the speed of the ball at the bottom of the ramp because that's what you measure to see how height affects it (use a stopwatch and meter stick to calculate speed—speed depends on height, changes in response to changing height). The controlled variables include ramp surface material (same for all), mass of the ball (same ball each time)—keeping these constant ensures that any speed differences observed are due to height changes, not other factors. Choice C is correct because it correctly identifies the dependent variable as what you measure to observe effects. Choice A is wrong because it confuses variable types: calls the independent variable (starting height, which you change) the dependent variable, mixing up what you change vs what you measure. Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like low, medium, high), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like speed with stopwatch), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does mass affect speed?"—independent: mass (1 kg, 2 kg, 3 kg), dependent: speed (measure at bottom), controlled: height (same), surface (same)—by changing only mass and measuring only speed while controlling everything else, you can determine the relationship, which is the goal of variable-controlled experimentation.

Question 16

A student investigates: How does surface type affect how far a toy car rolls? The student rolls the same toy car with the same starting push on tile, carpet, and sandpaper. Which set of variables should be controlled (kept the same) to make this a fair test?

Surface type and toy car mass
Surface type and the distance the car rolls
Toy car mass and the starting push force (correct answer)
The distance the car rolls and the time it takes

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does surface type affect how far a toy car rolls?": The independent variable is surface type because that's what you deliberately change to test the effect (tile, carpet, sandpaper—you control the surface). The dependent variable is the distance the car rolls because that's what you measure to see how surface affects it (use a meter stick to measure distance for each surface—distance depends on surface, changes in response to changing surface). The controlled variables include toy car mass (same car for all trials), starting push force (same push each time)—keeping these constant ensures that any distance differences observed are due to surface changes, not other factors. Choice C is correct because it accurately lists controlled variables as factors kept constant for fair test. Choice A is wrong because it suggests changing multiple variables simultaneously, which would not be a fair test because you couldn't tell which variable caused the observed effect (includes surface type, which is independent, not controlled). Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like tile, carpet, sandpaper), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like distance with meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does force affect acceleration?"—independent: force (5 N, 10 N, 15 N), dependent: acceleration (measure with sensor), controlled: mass (same), surface (same), starting position (same)—by changing only force and measuring only acceleration while controlling everything else, you can determine the relationship (F = ma), which is the goal of variable-controlled experimentation.

Question 17

A student tests: How does surface type affect how far a ball rolls? They roll the same ball across wood, carpet, and rubber mat. To make the test fair, the student should change only the surface type. Which plan is the best fair test design?

Use different balls for each surface so the test goes faster
Change the surface type and also start with a stronger push on rough surfaces
Use the same ball and the same starting push each time, then measure distance traveled on each surface (correct answer)
Measure the ball's mass after each roll to see if it changed

Explanation: This question tests understanding of identifying and categorizing variables in a motion investigation: independent (what you change), dependent (what you measure), and controlled (what you keep the same). In any investigation testing how one factor affects another, you must identify three types of variables: (1) independent variable—the factor you deliberately change to test its effect (like changing mass to 1 kg, 2 kg, 3 kg, or applying weak, medium, strong force); (2) dependent variable—the factor you measure that responds to the independent variable changes (like measuring speed, distance traveled, or time to stop as the outcome); and (3) controlled variables—all other factors you keep constant to ensure a fair test (like using same ramp, same surface, same starting position so that changes in the dependent variable are due to the independent variable only, not other factors). For "How does surface type affect how far a ball rolls?": The independent variable is surface type because that's what you deliberately change to test the effect (wood, carpet, rubber mat—you control the surface). The dependent variable is distance traveled because that's what you measure to see how surface affects it (measure distance—responds to surface). The controlled variables include the ball (same each time), starting push (same force)—keeping these constant ensures fair test. Choice C is correct because it properly identifies the independent variable as what you change to test the question and keeps controlled variables same. Choice B is wrong because it suggests changing multiple variables simultaneously, which would not be a fair test because you couldn't tell which variable caused the observed effect (changing push along with surface). Designing investigations with proper variable control: (1) start with testable question identifying relationship to investigate (How does X affect Y?), (2) independent variable = X (what you'll change: pick at least 3 values to test, like wood, carpet, mat), (3) dependent variable = Y (what you'll measure: should be measurable with available tools, like distance with meter stick), (4) controlled variables = everything else (list all factors that could affect dependent variable, plan to keep each one constant across all trials), (5) procedure describes: how you'll change independent, how you'll measure dependent, how you'll control others, ensuring fair test throughout. Example investigation: "How does mass affect speed?"—independent: mass (1 kg, 2 kg, 3 kg), dependent: speed (measure), controlled: surface (same), push (none)—by changing only mass and measuring only speed while controlling everything else, you can determine the relationship, which is the goal of variable-controlled experimentation.

Question 18

A student designs an investigation with a cart on a ramp. Investigation question: How does the mass of the cart affect its speed at the bottom of the ramp?

Which choice lists the variables correctly as independent, dependent, and controlled?

Independent: ramp height; Dependent: cart mass; Controlled: speed at the bottom
Independent: cart mass; Dependent: speed at the bottom; Controlled: ramp height, ramp surface, and starting position (correct answer)
Independent: speed at the bottom; Dependent: cart mass; Controlled: ramp height
Independent: cart mass and ramp height; Dependent: speed at the bottom; Controlled: surface type

Question 19

A student wants to test: How does surface type affect how far a toy car rolls? The student uses the same toy car and gives it the same push each time, but tests on tile, carpet, and sandpaper.

Which set of variables should be controlled to make this a fair test?

Surface type and push strength
Distance traveled and time to stop
Toy car mass and the strength of the initial push (correct answer)
Surface type and distance traveled

Question 20

A student rolls the same ball down a ramp to investigate: How does the starting height on the ramp affect the ball's speed at the bottom?

Which variable should the student change on purpose (the independent variable)?

The ball's speed at the bottom
The starting height on the ramp (correct answer)
The time it takes to reach the bottom
The distance from the bottom where the student stands