Question

A block B, placed on a horizontal surface is pulled with initial velocity V. If the coefficient of kinetic friction between surface and block is μ, than after how much time, block will come to rest ? 

(A) (v/g) 

(B) (g/v) 

(C) (g/v) 

(D) (v/g)

Answer 1

Correct option: (A) (v/g)

Explanation:

v_f = v_o + at

here v_f = 0

v_o = v

0 = v + at

v = – at

a = (– v / t)

F = ma

i.e. mg = ma

g = a

g = (v / t) as a = (v / t) considering magnitude

t = (v / g)