Q. A lift is moving upwards with a uniform velocity $v$ in which a block of mass $m$ is lying. The frictional force offered by the block, when coefficient of the frictional is $\mu$, will be
A) Zero
B) $mg$
C) $\mu mg$
D) 2$\mu mg$
Explanation
(a) The mass $m$ is not moving with respect to the lift and also has no tendency to move. Hence, friction force acting on it is equal to zero
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.