Question
300 J of work is done in sliding a 2 kg block up an inclined plane of height 10 m. Taking g =10 m/s2, work done against friction is
200J
100 J
zero
1000 J
Solution
B.
100 J
Net work done in sliding a body up to a height h on inclined plane
= Work done against gravitational force + Work done against frictional force
⇒ W = Wg + Wf
W = 300 J
but , Wg = mgh = 2 × 10 × 10
= 200 J
Putting in Eq. (i), we get
300 = 200 + Wf
⇒ Wf = 300 - 200
Wf = 100 J
