Answer: 5 m s-2.
- A 2.5 m s-2
- B 7.5 m s-2
- C 5 m s-2
- D 10 m s-2
Correct answer: C. 5 m s-2
Explanation: On a frictionless incline a = g sinθ = 10 × sin30° = 10 × 0.5 = 5 m s-2 (independent of mass).
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.