Q. A $2\ kg$ mass starts from rest on an inclined smooth surface with inclination $30{^\circ}$ and length $2\ m$. How much will it travel before coming to rest on a frictional surface with frictional coefficient of 0.25
A) $4\ m$
B) $6\ m$
C) $8\ m$
D) $2\ m$
Explanation
(a) $v^{2} = u^{2} + 2as = 0 + 2 \times g\sin 30 \times 2 \Rightarrow v = \sqrt{20}$
Let it travel distance ‘$S$’ before coming to rest
$S = \frac{v^{2}}{2\mu g} = \frac{20}{2 \times 0.25 \times 10} = 4m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.