Answer: g/3.
- A g/3
- B g/2
- C 2g/3
- D g
Correct answer: A. g/3
Explanation: a = (2m - m)g/(2m + m) = mg/(3m) = g/3.
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.