Predict Collision Motion - Middle School Physical Science

1. What is the acceleration ratio if two objects collide with the same force and masses $m_A$ and $m_B$?

   $\frac{a_A}{a_B}=\frac{m_B}{m_A}$. Equal forces and $a = F/m$ give inverse mass ratio for accelerations.

2. A $1\,\text{kg}$ ball hits a wall; the wall pushes on the ball with $20\,\text{N}$. What force does the ball exert on the wall?

   $20\,\text{N}$ opposite the wall-on-ball force. Newton's Third Law: ball pushes wall with equal force, opposite direction.

3. Identify the correct comparison: if $m_A > m_B$ and they collide, which has larger acceleration magnitude?

   Object B; $|a_B| > |a_A|$ for the same force magnitude. Less mass means greater acceleration for the same force: $a = F/m$.

4. What is the correct statement about collision forces and contact time: do longer collisions change force-pair equality?

   No; forces remain equal and opposite at each instant of contact. Newton's Third Law holds true at every instant during contact.

5. Calculate $a_B$: a $5\,\text{kg}$ cart experiences the same $10\,\text{N}$. What is $a_B$?

   $a_B = 2\,\text{m/s}^2$. Apply $a = F/m = 10\,\text{N} / 5\,\text{kg}$.

6. What is the key rule about which objects feel the forces in a Third Law pair?

   Each force acts on a different object. Forces in a Third Law pair never act on the same object.

7. Two skaters push off; skater $A$ is $50\,\text{kg}$ and $B$ is $100\,\text{kg}$. Who has larger acceleration?

   Skater $A$ has the larger acceleration. Smaller mass experiences larger acceleration with equal forces.

8. Identify whether the Third Law force pair cancels when finding the net force on one object.

   No; the pair acts on different objects, so it does not cancel on one object. Forces on different objects can't cancel when finding net force on one.

9. What is the direction relationship between a Third Law force pair during a collision?

   Opposite directions along the same interaction line. Third Law pairs always point in opposite directions along their line of action.

10. A $1\,\text{kg}$ ball hits a $3\,\text{kg}$ ball; contact force magnitude is $12\,\text{N}$. Find each ball's $|a|$.

    $|a_1|=12\,\text{m/s}^2$, $|a_3|=4\,\text{m/s}^2$. Use $a=\frac{F}{m}$: $a_1=\frac{12}{1}=12$, $a_3=\frac{12}{3}=4$.

11. What does Newton's Third Law state about the forces two objects exert on each other?

    They exert equal-magnitude, opposite-direction forces on each other. This is the fundamental statement of Newton's Third Law.

12. What formula links acceleration to force and mass for one object during a collision?

    $\vec{a}=\frac{\vec{F}}{m}$. Newton's Second Law rearranged to solve for acceleration.

13. Identify the correct name for the two forces described by Newton's Third Law.

    An action–reaction force pair. Newton's Third Law describes pairs of forces between interacting objects.

14. Which force pair is a valid Third Law pair: hand on wall and wall on hand, or hand on wall and floor on hand?

    Hand on wall and wall on hand. Valid pairs involve the same two objects exerting forces on each other.

15. Identify the Newton's Third Law force pair when object A pushes on object B.

    Force of A on B and force of B on A (equal and opposite). Third Law pairs always involve two objects acting on each other.

16. Identify the action-reaction pair: "bat exerts force on ball" during a hit.

    Ball exerts force on bat. Action-reaction pairs describe forces between the same two objects.

17. Identify the correct comparison of force magnitudes when a truck collides with a car.

    The truck and car forces are equal in magnitude. Newton's Third Law applies regardless of object masses.

18. If object $A$ exerts a $+50\,\text{N}$ force on object $B$, what is $\vec{F}_{B\to A}$?

    $-50\,\text{N}$ (same line of action, opposite direction). Newton's Third Law: equal magnitude, opposite direction.

19. Find and correct the error: "In a collision, the heavier object exerts a larger force on the lighter object."

    Correct: Both objects exert equal-magnitude forces on each other. Newton's Third Law states forces are equal regardless of mass.

20. Find and correct the claim: "In a collision, the heavier object exerts a larger force on the lighter object."

    Correct: Both objects exert equal-magnitude, opposite-direction forces. The claim violates Newton's Third Law; forces are always equal.

21. A bowling ball hits a pin. Which object experiences the larger force during contact?

    Neither; both experience equal-magnitude forces. Newton's Third Law: forces are always equal regardless of mass.

22. What is the meaning of $F_{A\to B}$ in collision notation?

    The force exerted by object A on object B. Subscript notation shows which object exerts force on which.

23. What is true about the contact time in a collision for both objects?

    Both experience the interaction for the same time interval, $\Delta t$. Contact forces exist only during mutual contact.

24. Which statement is correct: action and reaction forces act on the same object or different objects?

    Different objects. Each force in the pair acts on a different object, never the same one.

25. What is the acceleration formula that explains why equal collision forces can cause different accelerations?

    $a=\frac{F}{m}$. From Newton's Second Law, acceleration equals force divided by mass.

26. Choose the correct statement: if $m_A = m_B$ in a head-on collision, how do $|a_A|$ and $|a_B|$ compare?

    They are equal: $|a_A| = |a_B|$. Equal masses and equal forces produce equal accelerations.

27. Find $a$ for a $2\,\text{kg}$ cart experiencing a $6\,\text{N}$ collision force.

    $3\,\text{m/s}^2$. Using $a = F/m = 6\text{ N}/2\text{ kg} = 3\text{ m/s}^2$.

28. Which option correctly describes where an action-reaction force pair acts during a collision?

    On two different objects, not on the same object. Action-reaction pairs always act on different objects, never the same one.

29. A $4\,\text{kg}$ object experiences $10\,\text{N}$ during collision. What is the acceleration magnitude?

    $2.5\,\text{m/s}^2$. Apply $a=\frac{F}{m}=\frac{10}{4}=2.5\,\text{m/s}^2$.

30. Two skaters push off. Skater A mass is $50\,\text{kg}$ and B is $75\,\text{kg}$. Who has greater $|a|$?

    Skater A ($50\,\text{kg}$) has greater $|a|$. Lighter skater accelerates more with equal push forces: $a=\frac{F}{m}$.

31. Two objects collide. Object A feels $-8\,\text{N}$ (left). What force does A exert on B?

    $+8\,\text{N}$ (right). Third Law pairs have equal magnitude but opposite direction.

32. What is the relationship between the accelerations if object $A$ and $B$ exert equal forces but have different masses?

    The smaller mass has the larger acceleration. Same force on different masses gives $a = F/m$, so smaller $m$ has larger $a$.

33. If object A pushes object B to the right during a collision, what is the direction of the force on A from B?

    To the left. Newton's Third Law: forces are always opposite in direction.

34. Which statement is correct: action–reaction forces act on the same object or on different objects?

    They act on different objects. Each force in the pair acts on a separate object, not the same one.

35. Find the missing mass: if $F = 12\,\text{N}$ causes $a = 3\,\text{m/s}^2$, what is $m$?

    $m = 4\,\text{kg}$. Rearrange $F = ma$ to get $m = F/a = 12/3$.

36. Find and correct the claim: "During collision, the bigger truck exerts more force on the small car."

    Correct: They exert equal-magnitude, opposite-direction forces. The claim violates Newton's Third Law; forces are always equal.

37. A car hits a truck with $5000\,\text{N}$ on the truck. What is the truck's force on the car?

    $5000\,\text{N}$ in the opposite direction. Newton's Third Law: equal magnitude, opposite direction.

38. Which option correctly identifies why action–reaction forces do not cancel each other?

    They act on different objects, so they cannot cancel on one object. Forces can only cancel if they act on the same object.

39. A $0.5\,\text{kg}$ ball and a $2\,\text{kg}$ ball collide with equal forces. What is $\frac{a_{0.5}}{a_2}$?

    $4$. Using $\frac{a_{0.5}}{a_2} = \frac{m_2}{m_{0.5}} = \frac{2}{0.5} = 4$.

40. A truck and a car collide with equal forces. Which object has the larger acceleration?

    The car (smaller mass). Equal forces but smaller mass means larger acceleration ($a=F/m$).

41. What is the magnitude relationship between collision forces on two interacting objects?

    Equal magnitudes: $|F_{A\to B}| = |F_{B\to A}|$. Third Law requires equal magnitudes regardless of object properties.

42. Identify the correct net force on object A: only B pushes A with $-8\,\text{N}$. What is $F_{\text{net},A}$?

    $F_{\text{net},A} = -8\,\text{N}$. With only one force acting, net force equals that force.

43. Which statement is correct: action–reaction forces cancel each other in a collision, yes or no?

    No; they act on different objects, so they do not cancel on one object. Forces act on separate objects, so they can't cancel on one object.

44. Find the missing force: $\vec{F}_{A\to B}= -12\,\text{N}$; what is $\vec{F}_{B\to A}$?

    $+12\,\text{N}$. Opposite sign indicates opposite direction with same magnitude.

45. Identify the action–reaction partner to the force of a bat on a ball during a hit.

    The force of the ball on the bat. By Newton's Third Law, the ball exerts an equal force back on the bat.

46. Identify the correct comparison of forces when a truck collides with a car.

    Truck-on-car force equals car-on-truck force in magnitude. Newton's Third Law applies regardless of object masses.

47. Which statement is correct: the larger object exerts a larger force, or both objects exert equal force?

    Both objects exert equal force on each other. Newton's Third Law: forces are always equal regardless of object sizes.

48. Identify the action–reaction partner to the force of a car bumper on another car in a collision.

    The force of the second car on the first car. Newton's Third Law: the second car pushes back with equal force.

49. What is the relationship between the magnitudes of forces in an action–reaction pair?

    Equal magnitudes. Newton's Third Law requires action-reaction forces to have the same magnitude.

50. What is the relationship between the directions of forces in an action–reaction pair?

    Opposite directions. Action-reaction forces point in exactly opposite directions along the same line.

51. A $0.02\,\text{kg}$ bug and a $1000\,\text{kg}$ car exert $F$ on each other. Which has larger $|a|$?

    The bug; $|a_{\text{bug}}| \gg |a_{\text{car}}|$. Much smaller mass yields much larger acceleration: $a = F/m$.

52. Find $a$ for a $6\,\text{kg}$ cart experiencing the same $6\,\text{N}$ collision force.

    $1\,\text{m/s}^2$. Using $a = F/m = 6\text{ N}/6\text{ kg} = 1\text{ m/s}^2$.

53. What is the direction relationship between forces in a Newton's Third Law pair?

    They point in opposite directions. Third Law pairs always point in opposite directions along the same line.

54. What is the action-reaction force relationship written as an equation for a collision?

    $\vec{F}_{A\rightarrow B}=-\vec{F}_{B\rightarrow A}$. Mathematical form shows forces are equal in magnitude but opposite in direction.

55. What does Newton's Third Law state about the forces two colliding objects exert?

    They exert equal-magnitude, opposite-direction forces on each other. Newton's Third Law: for every action, there's an equal and opposite reaction.

56. Identify the correct force pair: normal force and weight on a book, or book-on-table and table-on-book?

    Book-on-table and table-on-book. Action-reaction pairs involve forces between two objects, not on one object.

57. What does the phrase "equal and opposite" mean for collision forces, in terms of magnitude?

    The magnitudes are the same: $|F_{A o B}|=|F_{B o A}|$. "Equal" refers to magnitude; "opposite" refers to direction.

58. State the formula relating net force, mass, and acceleration used after a collision.

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

59. Identify the correct acceleration ratio if the same force acts on masses $m_1$ and $m_2$.

    $\frac{a_1}{a_2}=\frac{m_2}{m_1}$. From $F=ma$ with equal forces: accelerations are inversely proportional to masses.

60. During a collision, if the contact force magnitude increases, what happens to both objects' force magnitudes?

    Both increase equally (still opposite in direction). Action-reaction forces always have equal magnitudes at every instant.

61. A $2\,\text{kg}$ cart and a $6\,\text{kg}$ cart collide and exert equal forces. Which cart has greater $|a|$?

    The $2\,\text{kg}$ cart has greater $|a|$. Smaller mass has larger acceleration when forces are equal: $a=\frac{F}{m}$.

62. A bug hits a windshield. Which experiences the larger force magnitude during contact: bug or windshield?

    Neither; the force magnitudes are equal on both objects. Third Law applies regardless of size difference.

63. If $\vec{F}_{A\to B}$ points east, what direction does $\vec{F}_{B\to A}$ point?

    West. Action-reaction forces are always in opposite directions.

64. A $2\,\text{kg}$ cart and a $6\,\text{kg}$ cart push with equal force. Which has larger $|a|$?

    The $2\,\text{kg}$ cart. Smaller mass experiences larger acceleration when forces are equal ($a=F/m$).

65. What is the correct direction relationship between $\vec{F}_{A\rightarrow B}$ and $\vec{F}_{B\rightarrow A}$?

    They point in opposite directions. The negative sign in Newton's Third Law indicates opposite directions.

66. State the formula linking acceleration to net force and mass for one object in a collision.

    $a = \frac{F_{\text{net}}}{m}$. Newton's Second Law relates net force to acceleration.

67. Identify the reaction force to "ball pushes on wall" during a collision.

    Wall pushes on ball. Newton's Third Law: every action has an equal and opposite reaction.

68. Which option is correct in a collision: the heavier object exerts a larger force, or both exert equal force?

    Both exert equal force on each other. Mass doesn't affect force magnitude in Third Law pairs.

69. Which statement correctly describes an action–reaction force pair in a collision?

    Forces are equal in size and opposite in direction, on different objects. Third Law pairs always act on different objects, preventing cancellation.

70. Find the missing force: if $F_{A\to B} = +30\,\text{N}$, what is $F_{B\to A}$?

    $F_{B\to A} = -30\,\text{N}$. Third Law pairs have equal magnitude but opposite direction.

71. Calculate $a_A$: a $2\,\text{kg}$ cart experiences $10\,\text{N}$ during collision. What is $a_A$?

    $a_A = 5\,\text{m/s}^2$. Apply $a = F/m = 10\,\text{N} / 2\,\text{kg}$.

72. What happens to acceleration when the same force acts on a larger mass during a collision?

    Acceleration is smaller for the larger mass. From $a=\frac{F}{m}$: larger mass means smaller acceleration.

73. Which option is correct in a collision: the larger mass object exerts a larger force, or forces are equal?

    Forces are equal in magnitude (opposite in direction). Newton's Third Law applies regardless of object masses or sizes.

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