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 a toy car’s speed at the bottom?": The independent variable is starting height on the ramp because that's what you deliberately change to test the effect (different heights—you control it). The dependent variable is speed at the bottom because that's what you measure to see how height affects it (speed responds). The controlled variables include the toy car used (same car and wheels each trial)—keeping this constant ensures that any speed differences are due to height changes, not car differences. Choice C is correct because it accurately lists controlled variables as factors kept constant for fair test. Choice A is wrong because it lists independent variable as controlled, suggesting keeping constant what should be changed (height is what you vary). 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 force affect distance?"—independent: force (weak, medium, strong), dependent: distance (measure), controlled: car (same), surface (same)—by changing only force and measuring only distance while controlling everything else, you can determine the relationship, which is the goal of variable-controlled experimentation.

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.

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.

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.

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.

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.

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.

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.

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.

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.