Question

A block of mass 2 kg rests on a horizontal surface. If a horizontal force of 5 N is applied on the

block, coefficients of static and kinetic frictions are 0.4 and 0.2 respectively. the frictional force on it is

(a) 20 N

(b) zero

(c) 8 N

(d) 5 N
​

Answer 1

The correct option is (d), so the correct answer is 5N. The explanation to the question is given below.

Given: mass = 2kg

           horizontal force = 5N

           static friction coefficients = 0.4

           kinetic friction coefficient = 0.2

To find: Frictional force

Solution:

The frictional force is the hindrance force in the movement of the block. It refers to the force generated by two surfaces that contact and slide against each other.

The coefficient of friction signifies determining the roughness of the surface.

Frictional force = μN ( coefficient of kinetic  friction is used here)

                         = μmg = 0.4×2×10

                       f  = 8N

frictional force (static) > Horizontal force

Therefore, the frictional force = 5N

Therefore, the correct option is (d), so the correct answer is 5N