Question

A particle of mass $m$ slides along curved - flat - curved track. The curved portions of the track is smooth. If the particle is released at the top of one of the curved portions and the particle comes to rest at flat portion of length $l$ after covering a distance of (coefficient of kinetic friction is ${\mu }_k$):

• A. $\frac{l}{3{\mu }_k}$
• B. $\frac{H}{2{\mu }_k}$
• C. $\frac{l}{6}$
• D. $\frac{H}{{\mu }_k}$

Answer 1

The correct option is D $\frac{H}{{\mu }_k}$

P.E $=$ Work done

$mgH={\mu }_{k}NS={\mu }_{k}mg{l}^{\prime }$ where $N=mg$ is the normal reaction

or $l^{\prime }=\frac{H}{{\mu }_k}$