Question

A boy of mass 30 kg starts running from rest along a circular path of radius 6 m with constant tangential acceleration of magnitude 2 m s^–2. After 2 s from start he feels that his shoes started slipping on ground. The friction between his shoes and ground is (Take g = 10 m s^–2) 

(a) 1/2 

(b) 1/3 

(c) 1/4 

(d) 1/5

Answer 1

Correct option (b)

Explanation:

After 2s, speed of boy will be

v = 2 x 2 = 4m s^–1

At this moment, centripetal force on the boy is