Question

A body of mass 2 kg is being dragged with a uniform velocity of 2 ms^-1 on a horizontal plane. The coefficient of friction between the body and the surface is 0.2. Work done in 5s is

• A. 39.2 J
• B. 9.32J
• C. 23.9J
• D. 93.2J

Answer 1

Answer: (A)

39.2 J

Answer 2

Normal reaction,

R = mg = 2 × 9.8 N

Frictional force

F = μR = 0.2 × 2 × 9.8 = 3.92 N

Distance traveled

5s = S i.e., 2 × 5 = 10 m

∴ Work done = F × S = 3.92 × 10 = 39.2 J