Answer: 12 N.
- A 6 N
- B 30 N
- C 18 N
- D 12 N
Correct answer: D. 12 N
Explanation: Acceleration a = m(hang)g/(total mass) = 3 × 10 / 5 = 6 m s<sup>-2</sup>. Tension = m(table) × a = 2 × 6 = 12 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.