Question

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.

• A. $\frac{v}{g\mu }$
• B. $\frac{g\mu }{v}$
• C. $\frac{g}{v}$
• D. $\frac{v}{g}$

Answer 1

The correct option is A $\frac{v}{g\mu }$

Friction force of the block will be, $F=\mu mg$

So retardation will be, $a=\frac{F}{m}=\mu g$

Using: $v=u+at$

We get, $t=\frac{v}{\mu g}$