Question

When the engine is switched off a vehicle of mass ${}^{\prime }{M}^{\prime }$ is moving in a rough horizontal road with momentum $P$. If the coefficient of friction between the road and tires of the vehicle is ${\mu }_k$, the distance traveled by the vehicle before it comes to rest is:

Answer 1

In such question for finding distance 3rd equation of motion is used :$s=\frac{v^2-u^2}{2a}$

in this question , $u=\frac{P}{M},v=0,a=-{\mu }_{k}g$

so , $s=\frac{0-(P/M{)}^2}{-{\mu }_{k}g}=\frac{P^2}{{\mu }_{k}g{M}^2}$