Q.
Two identical masses $A$ and $B$ are hanging stationary by a light pulley (shown in the figure). A shell $C$ moving upwards with velocity $v$ collides with the block $B$ and gets stick to it. Then
A) First string becomes slack and after some time becomes taut
B) The momentum conservation principle is applicable to $B$ and $C$
C) The string becomes taut only when down displacement of combined mass $B$ and $C$ is occurred
D) Both (a) and (b) are correct
Explanation
(d) When $C$ collides with $B$ then due to impulsive force, combined mass ($B + C$) starts to move upward. Consequently the string becomes slack
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.