Question

A block of mass 20 kg is acted upon by a force F = 30 N at an angle 53° with the horizontal in downward direction as shown. The coefficient of friction between the block and the horizontal surface is 0.2. The friction force acting on the block by the ground is (g = 10 m/s² ) 

(A) 40.0 N 

(B) 30.0 N 

(C) 18.0 N 

(D) 44.8 N

Answer 1

Correct option: (C) 18.0 N

Explanation:

= 0.2 (20 × 10 + 30 × 4/5 ) = 44.8 N

As applied horizontal force is F cos 53°3

= 18N < f_max , friction force will also be 18 N.