Answer: 4 N.
- A 4 N
- B 6 N
- C 10 N
- D 2 N
Correct answer: A. 4 N
Explanation: Acceleration = 10/5 = 2 m/s²; contact force pushes the 2 kg block: F = 2·2 = 4 N.
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.