Answer: 15 N.
- A 10 N
- B 15 N
- C 20 N
- D 25 N
Correct answer: B. 15 N
Explanation: a = 5 m/s<sup>2.</sup> T = m<sub>1</sub> x a = 3 x 5 = 15 N (tension accelerates the 3 kg block).
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.