Question

An accelerated system with a vertical wall has co-efficient of friction µ between block and walls as shown in the figure. A block M of mass 1 kg just remains in equilibrium with the vertical wall, when the system has an acceleration of 20 m/s². The co-efficient of friction has a value

(A) 0.10

(B) 0.25

(C) 0.50

(D) 1

Answer 1

Correct option is (C) 0.50

According to the problem the mass of the block is m = 1 kg

The acceleration of the cart is a = 20 m/s²

In this problem a force is working on the opposite direction of the acceleration

Let the force be f = mg

Therefore from newton's 2nd law,

N = ma

Let the coefficient friction of block be μ

Now the frictional force will be,

f = μN

mg = μ x ma

g = μ a

μ = g/a

If we assume g = 10 m/s²

therefore μ = 10/20

μ = 0.5