Question

Work done in sliding a 1 kg block up a rough inclined plane of height 5 m is 100 J. Work done against the friction is ______.

(g = 10 m/s²)

Options

• 75 J

• 25 J

• 50 J

• 100 J

Answer 1

Work done in sliding a 1 kg block up a rough inclined plane of height 5 m is 100 J. Work done against the friction is 50 J.

Explanation:

Total work done W = W₁ + W₂

where W₁ = work done against gravity

and W₂ = work done against friction

W = 100 J,

W₁ = mgh = 1 × 10 × 5 = 50 J

W₂ = W - W₁ = 100 - 50 = 50 J