A block `B` is pushed momentarily along a horizontal surface with an initial velocity `v` . If mu is the coefficient of sliding friction between `B` and the surface, block `B` will come to rest after a time:

Options

A. `(v)/(g mu)`
B. `(g mu)/(v)`
C. `(g)/(v)`
D. `(v)/(g)`

Answer

A

Explanation

Block B will come to rest, if force applied to it will vanish due to friction acting between block B and surface i.e. force applied = frictional force
i.e. `mu mg = ma` or `mu mg = m ((v)/(t))`
or `t = (v)/(mu g)`