Question

A body of mass 5kg rests on a rough horizontal surface of coefficient of friction 0.2. The body is pulled through a distance of 10m by a horizontal force of 25 N. The kinetic energy acquired by it is (g = 10 ms²)

• A. 330 J
• B. 150 J
• C. 100 J
• D. 50 J

Answer 1

Answer: (B)

150 J

Answer 2

Kinetic energy acquired by body = Total work done on the body – Work done against friction

= $F \times S - \mu mgS$ = 25 × 10 – 0.2 × 5 × 10 ×10 = 250 – 100

= 150 J.