Q.
Two blocks $m_{1}$ and $m_{2}$ ($m_{2} > m_{1}$) are connected with a spring of force constant $k$ and are inclined at a angel $\theta$ with horizontal. If the system is released from rest, which one of the following statements is/are correct?
A) Maximum compression in the spring $\frac{\left( m_{1} + m_{2} \right)g\ sin\ \theta}{k}$ if there is no friction anywhere
B) There will be no compression or elongation in the spring if there is no friction any where
C) If $m_{1}$ is smooth and $m_{2}$ is rough there will be compression in the spring
D) Maximum elongation in the spring is $\frac{\left( m_{1} - m_{2} \right)g\ sin\theta\ }{k}$ if all the surfaces are smooth
Explanation
(b) If the surface is smooth, then relative acceleration between blocks is zero. So, no compression or elongation takes place in spring. Hence, spring force on blocks is zero.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.