AP Physics C Mechanics 2.3 Third Law Overview
Describe paired forces between interacting objects and distinguish the equal-and-opposite forces in a Newton’s third-law interaction.
- Syllabus
- Effective Fall 2025
- Course
- AP Physics C: Mechanics
Covered syllabus points
2.3 Newton’s Third Law question 1
[Maximum number: 2]
Cart 1 of mass m1 is held at rest above the bottom of an incline. Cart 2 has mass m2, where m2>m1, and is at rest at the bottom of the incline. At time t=0, Cart 1 is released and then travels down the incline and smoothly transitions to the horizontal section. The center of mass of Cart 1 moves a vertical distance of H, as shown. At time tC, Cart 1 reaches the bottom of the incline and immediately collides with and sticks to Cart 2. After the collision, the two-cart system moves with constant speed v. Frictional and rotational effects are negligible.
During the collision, is the impulse on Cart 1 from Cart 2 greater than, less than, or equal to the magnitude of the impulse on Cart 2 from Cart 1 ?
Greater than Less than Equal to
Justify your answer.
For selecting "Equal to" with an attempt at a relevant justification
1 point
For a correct justification
1 point
Example Response
Newton's third law says equal/opposite forces, time intervals are same during same collision, so magnitudes of impulse must be equal.
Total for part (a)
2 points
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