AP EAMCET202119 Aug 2021Morning ShiftPhysicsMotion in One DimensionActual
An object dropped in a stationary lift takes time t 1 to reach the floor. It takes time t 2 when lift is moving up with constant acceleration. Then
Options
- At 2 > t 1
- Bt 1 > t 2
- Ct 1 ≈ t 2
- Dt 1 = t 2
Correct answer
B. t 1 > t 2
Step-by-step solution
When the object is dropped in a stationary lift from height h , s = u t + 1 2 a t 2 - h = 0 t 1 + 1 2 - g t 1 2 t 1 = 2 h g When the object is dropped from a lift which is moving up with an acceleration a ,   then a pseudo force will act on the object since the object is in a non-inertial frame of reference, therefore net acceleration due to gravity and pseudo force on the object will be, - g + a   in the downward direction. ⇒ s = u t + 1 2 a t 2 ⇒ - h = 0 t + 1 2 - g + a t 2 2 ⇒ t 2 = 2