Answer: 2 m s-1.
- A 1 m s-1
- B 5 m s-1
- C 2.5 m s-1
- D 2 m s-1
Correct answer: D. 2 m s-1
Explanation: Conserving momentum: (2)(5) = (2 + 3)v, so v = 10/5 = 2 m s-1.
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.