Question

A 10 kg box is placed on surface. Coefficient of
friction between surface and box is u=0.5. If horizontal
force 100 N is applied acceleration of box will be
(g = 10 m/sec) -
[AIPMT-2002]​

Answer 1

Hey, there!

Here's your answer.

The normal reaction by the surface, here = mg = 10 × 10 N = 100N

Maximum frictional force that the surface can apply on the box = μmg = 0.5 × 100 = 50N

But the external force applied is 100N which is way too more than the frictional force, so the body has to accelerate.

Net force acting on the body

= 100N - 50N

= 50N

(this is because friction always opposes the motion)

☛ F = ma

Here,

50 = 10a

a = 50/10 = 5m/s² (ans)

Hope that helps.

Thanks.

Answer 2

First find friction then find net force acting on the block