Net Force and Motion - Middle School Physical Science

1. Which option best describes how acceleration changes if net force doubles and mass stays the same?

   Acceleration doubles. From $a = \frac{F}{m}$, if $F$ doubles, $a$ doubles.

2. What is the formula for acceleration in terms of net force and mass?

   $a = \frac{F_{net}}{m}$. Rearrange Newton's second law by dividing both sides by mass.

3. Find the mass when $F_{net} = 12\,\text{N}$ and $a = 3\,\text{m}/\text{s}^2$.

   $m = 4\,\text{kg}$. Rearrange to $m = F_{net}/a$: $12/3 = 4$ kg.

4. Find the acceleration when $F_{net} = 10\,\text{N}$ and $m = 2\,\text{kg}$.

   $a = 5\,\text{m}/\text{s}^2$. Rearrange to $a = F_{net}/m$: $10/2 = 5$ m/s².

5. Calculate acceleration if velocity changes from $0$ to $10\frac{\text{m}}{\text{s}}$ in $5\text{ s}$.

   $2\frac{\text{m}}{\text{s}^2}$. Apply $a = \frac{\Delta v}{\Delta t} = \frac{10-0}{5} = 2\frac{\text{m}}{\text{s}^2}$.

6. Identify the sign of acceleration if velocity changes from $+6$ to $+2\frac{\text{m}}{\text{s}}$ in $2\text{ s}$.

   Negative. Velocity decreases, so acceleration opposes motion direction.

7. Which option best describes how acceleration changes if $F_{net}$ doubles and mass stays constant?

   Acceleration doubles. From $a = \frac{F}{m}$, doubling $F$ doubles $a$ when $m$ is constant.

8. Identify the independent and dependent variables when testing how $F_{net}$ affects $a$ for constant $m$.

   Independent: $F_{net}$; dependent: $a$. We control $F_{net}$ (independent) and measure resulting $a$ (dependent).

9. What does a straight line through the origin on a graph of $F_{net}$ vs. $a$ indicate?

   Direct proportionality; slope equals mass $m$. Linear relationship through origin shows constant ratio $\frac{F_{net}}{a} = m$.

10. Choose the correct conclusion: an object moves right at constant speed; what is $F_{net}$?

    $F_{net} = 0$. Constant velocity means zero acceleration, so zero net force.

11. Calculate acceleration from data: velocity changes from $2$ to $8\ \text{m}/\text{s}$ in $3\ \text{s}$. What is $a$?

    $2\ \text{m}/\text{s}^2$. Using $a = \frac{\Delta v}{\Delta t} = \frac{8-2}{3} = 2$.

12. Calculate $m$ when $F_{\text{net}} = 18\ \text{N}$ and $a = 6\ \text{m}/\text{s}^2$.

    $3\ \text{kg}$. Using $m = \frac{F_{\text{net}}}{a} = \frac{18}{6}$.

13. Find the net force if forces of $7\ \text{N}$ north and $7\ \text{N}$ south act on an object.

    $0\ \text{N}$. Equal opposite forces cancel: $7 - 7 = 0\ \text{N}$.

14. Identify the best graph type to show how acceleration changes with net force using data pairs.

    Scatter plot (or line graph if connected in order). Shows relationship between two continuous variables from experiments.

15. What happens to an object's motion when $F_{net} = 0$?

    No acceleration; velocity stays constant (may be $0$). Newton's First Law: no net force means no change in motion.

16. What is the formula for Newton's Second Law relating net force, mass, and acceleration?

    $F_{net} = ma$. Newton's Second Law: force equals mass times acceleration.

17. What is the dependent variable when you change net force and measure motion change?

    Acceleration (change in velocity over time). The variable you measure as a result of changing net force.

18. What is the SI unit of acceleration?

    $\text{m}/\text{s}^2$. Meters per second squared measures change in velocity per second.

19. Identify the direction of acceleration compared with the direction of $F_{net}$.

    Acceleration is in the same direction as $F_{net}$. Force and acceleration are vectors pointing the same way.

20. What is the SI unit of acceleration?

    $\frac{\text{m}}{\text{s}^2}$. Acceleration measures velocity change per unit time.

21. What is the SI unit of force?

    Newton (N). Named after Sir Isaac Newton, equals $1\text{ kg}\cdot\frac{\text{m}}{\text{s}^2}$.

22. Calculate acceleration: $F_{net}=12\ \text{N}$ and $m=3\ \text{kg}$.

    $a = 4\ \text{m}/\text{s}^2$. Use $a=\frac{F_{net}}{m}=\frac{12}{3}=4$ m/s².

23. What is the formula for average velocity using displacement data over a time interval?

    $v=\frac{\Delta x}{\Delta t}$. Displacement divided by time gives average velocity.

24. What is the formula to compute acceleration from net force and mass?

    $a = \frac{F_{net}}{m}$. Rearrange $F_{net} = ma$ by dividing both sides by $m$.

25. What is the formula for acceleration when net force and mass are known?

    $a = \frac{F_{net}}{m}$. Rearranging Newton's second law by dividing both sides by mass.

26. Identify the net force if forces of $6\text{ N}$ left and $6\text{ N}$ right act on an object.

    $0\text{ N}$. Equal opposite forces cancel out completely.

27. Which quantity changes when a nonzero net force acts on an object: speed, velocity, or both?

    Velocity (speed and/or direction) changes. Force changes velocity; speed is just magnitude of velocity.

28. Calculate net force when $m = 5\text{ kg}$ and $a = 2\frac{\text{m}}{\text{s}^2}$.

    $10\text{ N}$. Apply $F_{net} = ma = 5\text{ kg} \times 2\frac{\text{m}}{\text{s}^2} = 10\text{ N}$.

29. What is the SI unit of force, expressed in base units?

    $1\ \text{N} = 1\ \text{kg}\cdot\text{m}/\text{s}^2$. Newton (N) is defined as kilogram-meter per second squared.

30. What is the SI unit of force and its equivalent base units?

    $1\ \text{N} = 1\ \text{kg}\cdot\text{m}/\text{s}^2$. Newton defined as the force to accelerate $1$ kg at $1$ m/s².

31. What is the SI unit of net force used when analyzing motion data?

    Newton (N), equal to $1\ \text{kg}\cdot\text{m}/\text{s}^2$. Force equals mass times acceleration in SI units.

32. Calculate the net force when $m = 5\ \text{kg}$ and $a = 2\ \text{m/s}^2$.

    $10\ \text{N}$. Use $F_{\text{net}} = ma = 5 \times 2 = 10$.

33. What is the definition of acceleration in terms of velocity and time?

    $a=\frac{\Delta v}{\Delta t}$. Change in velocity divided by time interval.

34. Calculate the acceleration when $F_{\text{net}} = 12\ \text{N}$ and $m = 3\ \text{kg}$.

    $4\ \text{m/s}^2$. Use $a = \frac{F_{\text{net}}}{m} = \frac{12}{3} = 4$.

35. Which graph best represents $a$ versus $m$ for constant $F_{net}$: increasing line or decreasing curve?

    Decreasing curve (inverse relationship). Inverse proportionality creates a hyperbolic curve.

36. Calculate acceleration for $m = 2\ \text{kg}$ and $F_{net} = 10\ \text{N}$.

    $5\ \text{m}/\text{s}^2$. Apply $a = \frac{F_{net}}{m} = \frac{10}{2} = 5$.

37. What is the operational meaning of net force in a data-based investigation?

    The vector sum of all measured forces on the object. Add forces as vectors, considering direction and magnitude.

38. Find the net force: $6\ \text{N}$ east and $6\ \text{N}$ west act on an object.

    $0\ \text{N}$. Equal opposite forces cancel out completely.

39. Calculate net force for $m = 3\ \text{kg}$ and $a = 4\ \text{m}/\text{s}^2$.

    $12\ \text{N}$. Apply $F_{net} = ma = 3 \times 4 = 12$.

40. What is the independent variable in a lab that changes net force to observe acceleration?

    Net force applied to the object. The variable you change to observe its effect on acceleration.

41. What is the definition of net force on an object?

    The vector sum of all forces acting on the object. Net force combines all individual forces as vectors.

42. State the formula for weight near Earth's surface using gravitational field strength.

    $W = mg$. Weight equals mass times gravitational acceleration (g ≈ 9.8 m/s²).

43. What change in motion occurs when a net force acts in the same direction as velocity?

    Speed increases (positive acceleration along the motion). Force and velocity in same direction causes speeding up.

44. Find $F_{\text{net}}$ if forces are $10\ \text{N}$ right and $6\ \text{N}$ left.

    $4\ \text{N}$ to the right. Subtract opposing forces: $10 - 6 = 4$.

45. If $F_{net}=0$, what happens to an object's velocity?

    Velocity stays constant (including staying at rest). Newton's First Law: no net force means no change in motion.

46. Choose the correct conclusion: If mass stays constant, doubling $F_{net}$ does what to $a$?

    It doubles $a$. Direct proportionality: $a \propto F_{net}$ when mass is constant.

47. What happens to acceleration if mass stays constant and net force doubles?

    Acceleration doubles. From $a = \frac{F_{net}}{m}$, doubling force doubles acceleration.

48. A graph shows $a$ vs. $F_{net}$ for constant mass. What does the slope represent?

    $\frac{1}{m}$. From $a = \frac{F_{net}}{m}$, slope equals $\frac{1}{m}$.

49. If mass stays constant, how does acceleration change when $F_{net}$ doubles?

    Acceleration doubles. From $a=\frac{F_{net}}{m}$, doubling $F_{net}$ doubles $a$.

50. Identify the relationship between acceleration and mass when net force is constant.

    Acceleration is inversely proportional to mass. From $a=\frac{F_{net}}{m}$: doubling mass halves acceleration.

51. Calculate net force: a $0.5\ \text{kg}$ object accelerates at $4\ \text{m}/\text{s}^2$. What is $F_{net}$?

    $2\ \text{N}$. Using $F_{net} = ma = 0.5 \times 4 = 2$.

52. Calculate mass when $F_{net} = 18\text{ N}$ and $a = 3\frac{\text{m}}{\text{s}^2}$.

    $6\text{ kg}$. Apply $m = \frac{F_{net}}{a} = \frac{18\text{ N}}{3\frac{\text{m}}{\text{s}^2}} = 6\text{ kg}$.

53. What is the formula that relates net force, mass, and acceleration in one dimension?

    $F_{net}=ma$. Newton's second law relates force, mass, and acceleration.

54. What does it mean if the net force on an object is $0\ \text{N}$?

    No acceleration; velocity is constant (may be $0$). Zero net force means no change in motion per Newton's first law.

55. What is the formula that relates net force, mass, and acceleration?

    $F_{net} = ma$. Newton's second law relates force, mass, and acceleration.

56. Find the net force: $8\ \text{N}$ right and $3\ \text{N}$ left act on an object.

    $5\ \text{N}$ right. Subtract opposing forces: $8-3=5$ N in the right direction.

57. What does it mean if the net force on an object is $0\ \text{N}$?

    No acceleration; velocity stays constant (may be $0$). Newton's first law: no net force means no change in motion.

58. What does Newton's first law predict about motion when $F_{net}=0$?

    Velocity is constant (rest or constant speed in a straight line). No net force means no change in motion state.

59. What happens to acceleration if $F_{net}$ doubles while mass stays the same?

    Acceleration doubles. Direct proportionality: twice the force, twice the acceleration.

60. Identify the direction of acceleration relative to the direction of $F_{net}$.

    Acceleration is in the same direction as $F_{net}$. Newton's Second Law: force and acceleration vectors align.

61. What is the SI unit of force, and what base units equal it?

    Newton; $1\ \text{N} = 1\ \text{kg}\cdot\text{m}/\text{s}^2$. Force unit honors Isaac Newton; derived from $F=ma$.

62. Choose the correct relationship between acceleration and net force for constant mass.

    $a \propto F_{\text{net}}$. Direct proportionality: $a$ increases linearly with $F_{\text{net}}$.

63. Which statement is correct: net force causes velocity, or net force causes change in velocity?

    Net force causes change in velocity (acceleration). Force doesn't maintain velocity; it changes it.

64. What is the best definition of net force on an object?

    The vector sum of all forces acting on the object. Net force combines all individual forces as vectors.

65. What does a force arrow's length represent in a force diagram?

    The magnitude (size) of the force. Longer arrows represent stronger forces proportionally.

66. What is the slope meaning on a velocity–time graph for a moving object?

    Acceleration. Slope shows how velocity changes per unit time.

67. Calculate the net force when $m = 2\ \text{kg}$ and $a = 3\ \frac{m}{s^2}$.

    $6\ \text{N}$. Apply $F_{net} = ma = 2 \times 3 = 6\ \text{N}$.

68. A cart's net force stays constant. If mass doubles, what happens to acceleration?

    It becomes half as large. Inverse proportionality: doubling mass halves acceleration.

69. Two trials use the same object: $F_{net}$ doubles. What happens to $a$ if mass stays constant?

    Acceleration doubles. From $a = \frac{F_{net}}{m}$: doubling $F_{net}$ doubles $a$.

70. What does the slope represent on a graph of $a$ (y-axis) versus $F_{net}$ (x-axis)?

    Slope equals $\frac{1}{m}$. From $a = \frac{F_{net}}{m}$, the slope of $a$ vs $F_{net}$ is $\frac{1}{m}$.

71. Identify the net force when $+6\ \text{N}$ and $-2\ \text{N}$ act along the same line.

    $+4\ \text{N}$. Add forces algebraically: $(+6) + (-2) = +4$.

72. What is the formula that relates net force, mass, and acceleration?

    $F_{net} = ma$. Newton's second law relates force, mass, and acceleration.

73. Two forces of $10\,\text{N}$ east and $6\,\text{N}$ west act on an object. What is $F_{net}$?

    $4\,\text{N}$ east. Subtract opposing forces: $10-6=4\,\text{N}$ in east direction.

74. What is the condition for zero net force when analyzing a force table or free-body diagram?

    All forces balance so the vector sum is $F_{net}=0$. Equal and opposite forces cancel out completely.

75. Find the net force when $m = 2\,\text{kg}$ and $a = 3\,\text{m}/\text{s}^2$.

    $F_{net} = 6\,\text{N}$. Apply $F_{net} = ma$: $2 \times 3 = 6$ N.

76. Calculate $F_{net}$ when $m=2\,\text{kg}$ and $a=5\,\text{m/s}^2$.

    $10\,\text{N}$. Using $F_{net}=ma=2\times 5=10\,\text{N}$.

77. What does it mean if the net force on an object is $0\ \text{N}$?

    No acceleration; velocity stays constant (including rest). Newton's First Law: no net force means no change in motion.

78. What is the SI unit of force, and what base units is it equal to?

    Newton (N); $1\,\text{N} = 1\,\text{kg}\cdot\text{m}/\text{s}^2$. One Newton accelerates 1 kg at 1 m/s².

79. State the formula that relates net force, mass, and acceleration.

    $F_{\text{net}} = ma$. Newton's Second Law equation.

80. Calculate $F_{net}$ when a $10\ \text{N}$ force right and $6\ \text{N}$ force left act on an object.

    $4\ \text{N}$ to the right. Subtract opposing forces: $10-6=4$ N rightward.

81. Calculate the acceleration for $F_{net}=12\,\text{N}$ and $m=3\,\text{kg}$.

    $a = 4\,\text{m}/\text{s}^2$. Using $a = \frac{F_{net}}{m} = \frac{12\,\text{N}}{3\,\text{kg}} = 4\,\text{m}/\text{s}^2$.

82. If net force stays constant, how does acceleration change when mass doubles?

    Acceleration is cut in half. From $a=\frac{F_{net}}{m}$, doubling $m$ halves $a$.

83. Calculate $m$ when $F_{net}=18\,\text{N}$ and $a=6\,\text{m/s}^2$.

    $3\,\text{kg}$. Using $m=\frac{F_{net}}{a}=\frac{18}{6}=3\,\text{kg}$.

84. Which quantity changes when a nonzero net force acts on an object: speed, direction, or both?

    Both; a nonzero net force causes acceleration (change in velocity). Acceleration changes velocity, which includes both speed and direction.

85. What is the correct net force when $10\ \text{N}$ right and $6\ \text{N}$ left act on an object?

    $4\ \text{N}$ to the right. Subtract opposing forces: $10-6=4$ N rightward.

86. What happens to acceleration if net force stays constant and mass doubles?

    Acceleration is cut in half. From $a = \frac{F_{net}}{m}$, doubling mass halves acceleration.

87. What is Newton's second law formula relating net force, mass, and acceleration?

    $F_{net} = ma$. Shows net force equals mass times acceleration.

88. Calculate acceleration from data: velocity changes from $2$ to $10\,\text{m/s}$ in $4\,\text{s}$.

    $2\,\text{m/s}^2$. Using $a = \frac{\Delta v}{\Delta t} = \frac{10-2}{4} = 2$ m/s².

89. What is the formula for acceleration using two velocity measurements and a time interval?

    $a=\frac{\Delta v}{\Delta t}$. Change in velocity divided by time gives acceleration.

90. Identify the best conclusion if data show $a$ increases linearly as $F_{net}$ increases for the same cart.

    $a$ is directly proportional to $F_{net}$ for constant $m$. Linear relationship confirms Newton's Second Law.

91. What is the formula that relates net force, mass, and acceleration?

    $F_{net} = ma$. Newton's second law relates force to mass times acceleration.

92. Choose the correct conclusion: If $F_{net}$ stays constant, doubling $m$ does what to $a$?

    It halves $a$. Inverse proportionality: $a \propto 1/m$ when force is constant.

93. A force vs. acceleration graph is a straight line through the origin. What does the slope represent?

    Mass ($m$). From $F = ma$, slope $= \frac{F}{a} = m$ for linear relationship.

94. A graph shows $F_{net}$ vs. $a$ for constant mass. What does the slope represent?

    $m$. From $F_{net} = ma$, slope equals mass.

95. Identify the direction of acceleration relative to the net force direction.

    Acceleration is in the same direction as $F_{net}$. Newton's second law: force and acceleration vectors point the same way.

96. What is the difference between mass and weight?

    Mass is amount of matter; weight is gravitational force on mass. Mass is intrinsic; weight depends on gravity.

97. Identify the net force when forces of $6\,\text{N}$ up and $6\,\text{N}$ down act together.

    $F_{net} = 0\,\text{N}$. Equal opposite forces cancel completely.

98. Identify the net force when two forces of $10\,\text{N}$ and $6\,\text{N}$ act in the same direction.

    $16\,\text{N}$ in the common direction. Same-direction forces add: $10\,\text{N} + 6\,\text{N} = 16\,\text{N}$.

99. What does the slope of a velocity–time graph represent?

    Acceleration. Slope = rise/run = $\frac{\Delta v}{\Delta t}$ = acceleration.

100. Identify the formula for acceleration in terms of net force and mass.

     $a = \frac{F_{net}}{m}$. Rearranged from $F_{net} = ma$ by dividing both sides by $m$.

101. Which option best describes how acceleration changes if mass doubles and $F_{net}$ stays constant?

     Acceleration is cut in half. From $a = \frac{F}{m}$, doubling $m$ halves $a$ when $F$ is constant.

102. What is the formula for net force when mass and acceleration are known?

     $F_{net} = ma$. Direct application of Newton's second law.

103. What happens to an object's motion when the net force is $0\ \text{N}$?

     It has no acceleration; velocity stays constant. Newton's first law: no net force means no change in motion.

104. Identify the relationship between mass and acceleration if net force stays constant.

     $a$ is inversely proportional to $m$. Doubling mass halves acceleration when $F_{net}$ is fixed.

105. What change in motion occurs when a net force acts perpendicular to the velocity?

     Direction changes (object turns; speed may stay constant). Perpendicular force causes circular or curved motion.

106. Calculate $a$ when $F_{net}=12\,\text{N}$ and $m=3\,\text{kg}$.

     $4\,\text{m/s}^2$. Using $a=\frac{F_{net}}{m}=\frac{12}{3}=4\,\text{m/s}^2$.

107. What is the SI unit of force?

     newton (N). Named after Sir Isaac Newton.

108. Which quantity changes when a nonzero net force acts on an object: velocity or mass?

     Velocity. Force changes motion (velocity), not the amount of matter.

109. A cart moves right but slows down. Which direction must $F_{\text{net}}$ point?

     To the left. Deceleration means acceleration opposes velocity.

110. Identify the net force from an acceleration–time graph segment where $a=0\ \text{m}/\text{s}^2$ and $m$ is constant.

     $F_{net}=0\ \text{N}$. Zero acceleration means zero net force by $F_{net}=ma$.

111. What is the formula for net force in terms of mass and acceleration?

     $F_{net} = ma$. Newton's second law states net force equals mass times acceleration.

112. Identify the correct graph relationship between $a$ and $m$ for constant $F_{net}$.

     Inversely proportional; $a$ decreases as $m$ increases. When $F_{net}$ is constant, $a\propto\frac{1}{m}$ shows inverse relationship.

113. Which statement is correct when $F_{net}=0$ for an object?

     Velocity is constant (object is at rest or moves at constant speed in a straight line). Newton's First Law: no net force means no acceleration.

114. Which statement is correct: If $F_{net}$ stays constant, $a$ is proportional to $m$ or $\frac{1}{m}$?

     $a$ is proportional to $\frac{1}{m}$. From $a = \frac{F_{net}}{m}$, acceleration varies inversely with mass.

115. Identify the type of graph that best shows how acceleration changes with net force.

     A line graph (or scatter plot with best-fit line). Shows relationship between two continuous variables.

116. Choose the correct claim: If $F_{\text{net}}$ is constant, then acceleration is constant (for constant mass).

     True. From $a = \frac{F_{\text{net}}}{m}$, constant $F$ gives constant $a$.

117. Identify the slope meaning on a graph of $a$ (y-axis) versus $F_{net}$ (x-axis) for constant mass.

     Slope $= \frac{1}{m}$. From $a = F_{net}/m$, slope represents reciprocal of mass.

118. State Newton's second law in equation form using net force, mass, and acceleration.

     $F_{\text{net}} = ma$. Newton's second law relates force, mass, and acceleration.

119. State Newton's Second Law in equation form for net force.

     $F_{net}=ma$. Shows that net force equals mass times acceleration.

120. What is the definition of net force on an object?

     Net force is the vector sum of all forces on the object. Vector sum means adding forces considering both magnitude and direction.

121. What is the definition of net force on an object?

     The vector sum of all forces acting on the object. Forces combine as vectors, considering both magnitude and direction.

122. Which option best describes the motion if a cart moves right but $F_{net}$ points left?

     It accelerates left; it slows down while moving right. Leftward force opposes rightward motion, causing deceleration.

123. Which calculation finds average acceleration from velocity data over a time interval?

     $a = \frac{\Delta v}{\Delta t}$. Acceleration is change in velocity over time.

124. What does it mean if $F_{net} = 0$ for an object's motion?

     No acceleration; velocity is constant (may be $0$). Zero net force means no change in motion (Newton's first law).

125. Identify the net force if forces of $8\text{ N}$ right and $3\text{ N}$ left act on an object.

     $5\text{ N}$ to the right. Subtract opposing forces: $8\text{ N} - 3\text{ N} = 5\text{ N}$ right.

126. What does a force arrow's direction represent in a force diagram?

     The direction the force acts. Arrows point in the direction forces push or pull.

127. Identify the slope meaning on a graph of $F_{net}$ (y-axis) versus $a$ (x-axis) for constant mass.

     Slope $= m$. From $F_{net} = ma$, slope represents the object's mass.

128. Identify the relationship between acceleration and net force when mass is constant.

     Acceleration is directly proportional to net force. From $F_{net}=ma$: doubling force doubles acceleration.

129. Identify the correct graph relationship between $a$ and $F_{net}$ for constant $m$.

     Directly proportional; a straight line through the origin. When $m$ is constant, $a\propto F_{net}$ gives a linear relationship.

130. Identify the relationship between net force and acceleration if mass stays constant.

     $a$ is directly proportional to $F_{net}$. Doubling force doubles acceleration when $m$ is fixed.

131. Identify the net force when $10\,\text{N}$ right and $6\,\text{N}$ left act on an object.

     $4\,\text{N}$ to the right. Opposite forces subtract: $10\,\text{N} - 6\,\text{N} = 4\,\text{N}$ right.

132. Identify the mass if $F_{net}=18\,\text{N}$ produces $a=3\,\text{m}/\text{s}^2$.

     $m = 6\,\text{kg}$. Using $m = \frac{F_{net}}{a} = \frac{18\,\text{N}}{3\,\text{m}/\text{s}^2} = 6\,\text{kg}$.

133. Which quantity changes when an object accelerates: speed, direction, or both?

     Both speed and/or direction can change. Acceleration is any change in velocity vector (magnitude or direction).

134. Which graph best shows constant net force on constant mass: $v$ vs. $t$ is curved or a straight line?

     A straight line on a $v$ vs. $t$ graph. Constant force gives constant acceleration, making linear $v$ vs. $t$.

135. What is the SI unit of mass?

     Kilogram (kg). The fundamental SI unit for measuring matter's quantity.

136. Calculate acceleration when $F_{net} = 12\text{ N}$ and $m = 3\text{ kg}$.

     $4\frac{\text{m}}{\text{s}^2}$. Apply $a = \frac{F_{net}}{m} = \frac{12\text{ N}}{3\text{ kg}} = 4\frac{\text{m}}{\text{s}^2}$.

137. Find the net force from data: $m = 3\,\text{kg}$ and measured $a = 2\,\text{m}/\text{s}^2$.

     $F_{net} = 6\,\text{N}$. Apply $F_{net} = ma$: $3 \times 2 = 6$ N.

138. A cart's mass stays constant. If $F_{net}$ doubles, what happens to the cart's acceleration?

     It doubles. Direct proportionality: doubling force doubles acceleration.

139. Which graph best represents $a$ versus $F_{net}$ for constant mass: flat line or straight line through origin?

     Straight line through the origin. Direct proportionality creates a linear relationship through origin.

140. Calculate the acceleration when $F_{net} = 12\ \text{N}$ and $m = 3\ \text{kg}$.

     $4\ \frac{m}{s^2}$. Apply $a = \frac{F_{net}}{m} = \frac{12}{3} = 4\ \frac{m}{s^2}$.

141. If mass doubles while $F_{\text{net}}$ stays constant, what happens to acceleration?

     Acceleration is cut in half. From $a = \frac{F}{m}$: if $m$ doubles, $a$ halves.

142. Which quantity has the same direction as the net force: speed, velocity, or acceleration?

     Acceleration. Net force causes acceleration in the same direction.

143. Calculate the mass when $F_{net} = 20\ \text{N}$ and $a = 5\ \frac{m}{s^2}$.

     $4\ \text{kg}$. Apply $m = \frac{F_{net}}{a} = \frac{20}{5} = 4\ \text{kg}$.

144. Identify the best graph to test how net force affects acceleration while keeping mass constant.

     Plot $F_{net}$ on $y$ vs. $a$ on $x$ (straight line through origin). Linear graph shows direct proportionality between force and acceleration.

145. Identify the net force if forces are $5\ \text{N}$ up, $5\ \text{N}$ down, and no others.

     $0\ \text{N}$. Equal opposite forces cancel out.

146. State Newton's Second Law in words for how net force affects motion.

     Acceleration depends on net force and mass. Newton's Second Law describes the $F = ma$ relationship.

147. An object has $F_{net} = 0\ \text{N}$. Identify the acceleration.

     $0\ \frac{m}{s^2}$. From $a = \frac{F_{net}}{m}$: zero force means zero acceleration.

148. What is the SI unit of force, and what is it equal to in base units?

     Newton (N); $1\,\text{N} = 1\,\text{kg}\cdot\text{m}/\text{s}^2$. Force equals mass times acceleration in SI base units.

149. Calculate $a$ when $F_{\text{net}} = 12\ \text{N}$ and $m = 3\ \text{kg}$.

     $4\ \text{m}/\text{s}^2$. Using $a = \frac{F_{\text{net}}}{m} = \frac{12}{3}$.

150. What is the SI unit of acceleration written in base units?

     $\text{m}/\text{s}^2$. Acceleration measures change in velocity per unit time.

151. What is the acceleration if velocity changes from $2$ to $8\ \text{m}/\text{s}$ in $3\ \text{s}$?

     $2\ \text{m}/\text{s}^2$. Use $a=\Delta v/\Delta t=(8-2)/3=2$ m/s².

152. Calculate acceleration: $F_{net}=12\,\text{N}$ and $m=3\,\text{kg}$.

     $4\,\text{m/s}^2$. Using $a = \frac{F_{net}}{m} = \frac{12}{3} = 4$ m/s².

153. What is Newton's Second Law relating net force, mass, and acceleration?

     $F_{net} = ma$. This fundamental equation shows force equals mass times acceleration.

154. Which option best describes how acceleration changes if mass doubles and net force stays the same?

     Acceleration becomes half as large. From $a = \frac{F}{m}$, if $m$ doubles, $a$ halves.

155. Which graph best shows $F_{net}\propto a$: acceleration vs. net force is a straight line through what point?

     A straight line through $(0,0)$. Direct proportionality always passes through the origin.

156. A cart speeds up to the right. Which direction must $F_{\text{net}}$ point?

     To the right. Acceleration and net force point in same direction.

157. Identify the relationship between $F_{net}$ and $a$ when mass is constant.

     $a\propto F_{net}$. Direct proportionality: double force means double acceleration.

158. Which graph best shows constant net force on constant mass: velocity–time is a straight line or curved line?

     Straight line (constant slope, constant acceleration). Constant force produces constant acceleration (linear v-t).

159. Identify the net force when two opposite forces of $10\ \text{N}$ act on the same object.

     $0\ \text{N}$. Equal opposite forces cancel: $(+10) + (-10) = 0$.

160. If $F_{\text{net}}$ doubles while mass stays constant, what happens to acceleration?

     Acceleration doubles. From $a = \frac{F}{m}$: if $F$ doubles, $a$ doubles.

161. What is the definition of net force on an object?

     Net force is the vector sum of all forces acting on an object. It combines all forces considering both magnitude and direction.

162. What is the net force direction if measured acceleration is leftward for a constant-mass object?

     Leftward (same direction as the acceleration). Net force and acceleration always align in direction.

163. What does a nonzero net force imply about an object's motion in collected data?

     The object accelerates; its velocity changes. Unbalanced forces cause velocity to change.

164. Calculate $F_{net}$: forces of $+8\,\text{N}$ and $-3\,\text{N}$ act in one line.

     $5\,\text{N}$. $F_{net} = 8 + (-3) = 5$ N, adding with signs.

165. A graph of $F_{\text{net}}$ (y-axis) vs. $a$ (x-axis) is a straight line. What does the slope equal?

     $m$. From $F_{\text{net}} = ma$, slope equals mass.

166. What mass is implied by the data if $F_{net}=9\ \text{N}$ and $a=3\ \text{m}/\text{s}^2$?

     $3\ \text{kg}$. Use $m=F_{net}/a=9/3=3$ kg.

167. A $4\,\text{kg}$ cart has $a=1.5\,\text{m/s}^2$. What net force does the data imply?

     $6\,\text{N}$. Using $F_{net}=ma=4\times 1.5=6\,\text{N}$.

168. What is the SI unit of mass used in $F_{\text{net}} = ma$?

     Kilogram (kg). Standard SI unit for mass in physics calculations.

169. Which option describes balanced forces on an object?

     Forces cancel so $F_{net} = 0$. Equal and opposite forces result in zero net force.

170. Choose the correct relationship between acceleration and mass for constant net force.

     $a \propto \frac{1}{m}$. Inverse proportionality: $a$ decreases as $m$ increases.

171. Which statement is correct when $F_{net} = 0$ for an object's motion?

     Velocity is constant (could be zero or nonzero). Zero net force means no acceleration, so velocity doesn't change.

172. Calculate acceleration: a $2\ \text{kg}$ cart has $F_{net} = 6\ \text{N}$. What is $a$?

     $3\ \text{m}/\text{s}^2$. Using $a = \frac{F_{net}}{m} = \frac{6}{2} = 3$.

173. Calculate mass: $F_{net}=15\,\text{N}$ and $a=5\,\text{m/s}^2$.

     $3\,\text{kg}$. Using $m = \frac{F_{net}}{a} = \frac{15}{5} = 3$ kg.

174. Which quantity changes when a nonzero net force acts on an object?

     Velocity (speed and/or direction). Net force causes acceleration, which changes velocity.

175. Which option best describes how to use data to test $F_{net}=ma$ in a lab?

     Hold $m$ constant; vary $F_{net}$; check if $a$ is proportional to $F_{net}$. Control one variable while changing the other to test the relationship.

176. What is the slope meaning on a force–acceleration graph when mass is constant?

     Mass. Since $F = ma$, slope of F vs. a equals mass when m is constant.

177. Calculate mass: $F_{net} = 10\ \text{N}$ and $a = 2\ \text{m}/\text{s}^2$. What is $m$?

     $5\ \text{kg}$. Using $m = \frac{F_{net}}{a} = \frac{10}{2} = 5$.

178. A force vs. acceleration graph is a straight line through the origin. What does the intercept represent?

     $0\ \text{N}$ (no net force when $a = 0$). Line passes through origin: when $a = 0$, $F = 0$.

179. Find the net force if forces of $10\ \text{N}$ east and $4\ \text{N}$ west act on an object.

     $6\ \text{N}$ east. Opposite forces subtract: $10 - 4 = 6\ \text{N}$ in east direction.

180. Which direction is the acceleration relative to the net force in one-dimensional motion?

     Acceleration is in the same direction as $F_{net}$. Force and acceleration vectors point the same way.

181. Calculate $F_{\text{net}}$ when $m = 2\ \text{kg}$ and $a = 5\ \text{m}/\text{s}^2$.

     $10\ \text{N}$. Using $F_{\text{net}} = ma = 2 \times 5$.

182. What is the acceleration formula using change in velocity over time?

     $a = \frac{\Delta v}{\Delta t}$. Acceleration is the rate of velocity change.

183. What is the definition of net force on an object when multiple forces act on it?

     The vector sum of all forces acting on the object. Add all force vectors to find the net effect.

184. What is the direction of an object's acceleration compared with the direction of $F_{net}$?

     Acceleration is in the same direction as $F_{net}$. Newton's Second Law requires acceleration parallel to net force.

185. Identify the correct conclusion: If $F_{net}$ doubles and $m$ stays constant, what happens to $a$?

     $a$ doubles. From $a = \frac{F_{net}}{m}$, doubling force doubles acceleration.

186. If $F_{net}=0$, what is the acceleration of the object?

     $a=0\,\text{m/s}^2$. No net force means no acceleration by Newton's Second Law.

187. What is the acceleration if $F_{net}=12\ \text{N}$ and $m=3\ \text{kg}$?

     $4\ \text{m}/\text{s}^2$. Use $a=F_{net}/m=12/3=4$ m/s².

188. What is the definition of net force on an object?

     The vector sum of all forces acting on the object. Add all forces as vectors, considering direction.

189. What is the net force if $m=2\ \text{kg}$ and measured $a=5\ \text{m}/\text{s}^2$?

     $10\ \text{N}$. Use $F_{net}=ma=2×5=10$ N.

190. Which option describes unbalanced forces on an object?

     Forces do not cancel so $F_{net} \ne 0$. Unequal forces produce a nonzero net force.

191. Which statement is correct: If $m$ stays constant, $a$ is proportional to $F_{net}$ or $F_{net}^2$?

     $a$ is proportional to $F_{net}$. From $a = \frac{F_{net}}{m}$, acceleration varies directly with force.

192. Identify the net force when forces of $8\,\text{N}$ right and $3\,\text{N}$ left act together.

     $F_{net} = 5\,\text{N}$ right. Subtract opposing forces: $8 - 3 = 5$ N in dominant direction.

193. What pattern should a graph of $a$ versus $m$ show when net force is constant?

     Inversely proportional; as $m$ increases, $a$ decreases. From $a = \frac{F_{\text{net}}}{m}$, $a$ and $m$ vary inversely.

194. What happens to an object's motion when $F_{net} = 0$?

     No acceleration; velocity stays constant (including rest). Newton's First Law: objects maintain their state of motion without net force.

195. Which option best describes the relationship between $F_{net}$ and $a$ when mass is constant?

     Directly proportional: $a \propto F_{net}$. Acceleration increases linearly with net force when mass is fixed.

196. What is the SI unit of force?

     Newton (N). Named after Sir Isaac Newton, who formulated the laws of motion.

197. Find $F_{\text{net}}$ if forces are $7\ \text{N}$ left and $2\ \text{N}$ left.

     $9\ \text{N}$ to the left. Add forces in same direction: $7 + 2 = 9$.

198. What is the equation to calculate net force in one dimension from mass and acceleration data?

     $F_{net} = ma$. Newton's second law relates force, mass, and acceleration.

199. From data: $F_{net}=8\ \text{N}$ gives $a=2\ \text{m}/\text{s}^2$. What is the mass?

     $4\ \text{kg}$. Rearrange $F_{net} = ma$: $m = \frac{8}{2} = 4$.

200. Identify the acceleration direction if the net force is upward.

     Upward. Acceleration always points in the net force direction.

201. Calculate the net force for $m=5\,\text{kg}$ and $a=2\,\text{m}/\text{s}^2$.

     $F_{net} = 10\,\text{N}$. Using $F_{net} = ma = 5\,\text{kg} \times 2\,\text{m}/\text{s}^2 = 10\,\text{N}$.

202. Identify the controlled variable when testing how net force affects acceleration using a cart.

     Mass of the cart system. Keep mass constant to isolate force's effect on acceleration.

203. What pattern should a graph of $a$ versus $F_{\text{net}}$ show when mass is constant?

     Directly proportional; a straight line through the origin. From $a = \frac{F_{\text{net}}}{m}$, doubling $F$ doubles $a$.

204. Calculate the mass when $F_{\text{net}} = 18\ \text{N}$ and $a = 3\ \text{m/s}^2$.

     $6\ \text{kg}$. Use $m = \frac{F_{\text{net}}}{a} = \frac{18}{3} = 6$.

205. Two forces of $7\,\text{N}$ north and $7\,\text{N}$ south act on an object. What is $F_{net}$?

     $0\,\text{N}$. Equal opposite forces cancel out completely.

206. What is Newton's second law written as an equation relating net force, mass, and acceleration?

     $F_{net} = ma$. Newton's second law relates force, mass, and acceleration.

207. Identify the formula for net force in terms of mass and acceleration.

     $F_{net} = ma$. Newton's second law in its standard form.

208. Calculate net force: $m=2\,\text{kg}$ and $a=6\,\text{m/s}^2$.

     $12\,\text{N}$. Using $F_{net} = ma = 2 \times 6 = 12$ N.

209. A cart speeds up from $2\,\text{m/s}$ to $8\,\text{m/s}$ in $3\,\text{s}$. What is $a$?

     $2\,\text{m/s}^2$. Using $a=\frac{\Delta v}{\Delta t}=\frac{8-2}{3}=\frac{6}{3}=2\,\text{m/s}^2$.

210. Which option best describes the direction of acceleration compared with $F_{\text{net}}$?

     Acceleration is in the same direction as $F_{\text{net}}$. Force and acceleration are vector quantities with same direction.

211. A graph of $a$ (y-axis) vs. $F_{\text{net}}$ (x-axis) is a straight line. What does the slope equal?

     $\frac{1}{m}$. From $a = \frac{F_{\text{net}}}{m}$, slope equals $\frac{1}{m}$.

212. Identify the correct conclusion: If $m$ doubles and $F_{net}$ stays constant, what happens to $a$?

     $a$ becomes half as large. From $a = \frac{F_{net}}{m}$, doubling mass halves acceleration.

213. Identify the net force direction: an object's velocity is increasing to the right. Which way is $F_{net}$?

     To the right. Net force must be in the same direction as acceleration.

214. What change in motion occurs when a net force acts opposite the direction of velocity?

     Speed decreases (acceleration opposite the motion). Force opposing motion causes deceleration or slowing down.

215. Calculate mass: $F_{net}=18\ \text{N}$ and $a=6\ \text{m}/\text{s}^2$.

     $m = 3\ \text{kg}$. Use $m=\frac{F_{net}}{a}=\frac{18}{6}=3$ kg.

216. Which option describes the motion when $F_{net} \ne 0$?

     The object accelerates (speed and/or direction changes). Non-zero net force causes acceleration per Newton's second law.

217. Two trials use the same net force: mass doubles. What happens to $a$?

     Acceleration is cut in half. From $a = \frac{F_{net}}{m}$: doubling $m$ halves $a$.

218. What is the formula for net force when forces act along one line?

     $F_{net} = \sum F$. Sum all forces acting in the same line to find the net force.

219. Identify the relationship between mass and acceleration when $F_{net}$ is constant.

     $a\propto \frac{1}{m}$. Inverse proportionality: double mass means half acceleration.

220. State Newton's Second Law relating net force, mass, and acceleration.

     $F_{net}=ma$. Net force equals mass times acceleration.

221. State the formula for net force in one dimension using signed forces.

     $F_{net}=\sum F$. Sum symbol $\sum$ means add all forces with their signs.

222. What is the definition of acceleration in terms of velocity and time?

     $a=\frac{\Delta v}{\Delta t}$. Acceleration is the rate of change of velocity over time.

223. Identify the sign of $a$ if an object moves right but slows down.

     Negative acceleration (opposite the velocity direction). Slowing down means acceleration opposes velocity.

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