Answer: mv.
- A mv
- B mv/2
- C mv*sqrt(3)
- D 2mv cos60
Correct answer: A. mv
Explanation: Only normal component reverses. Normal component = v cos60 = v/2. Impulse = 2m x v/2 = mv.
Free-body diagram of a block on an incline: weight (mg) resolves into mg sinθ along the slope and mg cosθ into the slope, balanced by the normal force N and friction f.
Concept context
Newton's three laws, friction, circular motion, and free body diagrams.