Q. A block is at rest on an inclined plane making an angle $\alpha$ with the horizontal. As the angle $\alpha$ of the incline is increased, the block starts slipping when the angle of inclination becomes $\theta$. The coefficient of static friction between the block and the surface of the incline plane is or A body starts sliding down at an angle $\theta$ to horizontal. Then coefficient of friction equal to
A) $\sin\theta$
B) $\cos\theta$
C) $\tan\theta$
D) Independent of $\theta$
Explanation
(c) Coefficient of friction = Tangent of angle of repose
$\therefore\mu = \tan\theta$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.