The time period of oscillation of a simple pendulum of length L suspended from the roof of a vehicle, which moves without friction down an inclined plane of inclination α, is given by :
(A)2πL/(gcosα)✓ Correct
(B)2πL/(gsinα)
(C)2πL/g
(D)2πL/(gtanα)
Answer: (A)
Solution
When the vehicle moves down an inclined plane without friction, it accelerates with a=gsinα. In the non-inertial frame of the vehicle, a pseudo force acts on the pendulum. The effective gravity in this frame is geff=gcosα (perpendicular to the incline). The time period of the simple pendulum is T=2πgeffL=2πgcosαL.
JEE Main · 2022 · 29 Jul 2022 · Shift 1 · Single correct option