Q 11-04-026NEETJEE MainEAMCET 2008 (Engineering)Top questionEasy
Starting from rest, the time taken by a body sliding down on a rough inclined plane at $45°$ with the horizontal is twice the time taken to travel on a smooth plane of the same inclination and the same distance. Then the coefficient of kinetic friction is
Answer: (D) $0.75$
Concept. Same distance from rest: $a_s = 4a_r$.
Step 1. Equation. $1 = 4(1 - \mu_k)$.
Step 2. Solve. $\mu_k = 0.75$.
Answer. $0.75$ (Option D).
Solution by Sreeraj P, M.Sc Physics