Q. A body is moving in a room with a velocity of $20\ m/s$ perpendicular to the two walls separated by $5\ meters.$ There is no friction and the collisions with the walls are elastic. The motion of the body is
A) Not periodic
B) Periodic but not simple harmonic
C) Periodic and simple harmonic
D) Periodic with variable time period
Explanation
(b) Body collides elastically with walls of room. So, there will be no loss in its energy and it will remain colliding with walls of room after a regular time interval, so it’s motion will be periodic. Since acceleration is not proportional to displacement, so it’s motion is not SHM
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.