Question

 A simple pendulum has a period 2 second and is operated in a lift on earth 

what happen to its period 

i.) When the lift is ascending at uniform velocity

ii.) When the lift is ascending at an acceleration a m/s2

iii.) When the lift cable snaps?

Answer 1

The period of a simple pendulum is:

$$T = 2\pi\sqrt{\dfrac{l}{g}}$$

where $g$ is the acceleration of the pendulum and $l$ is its length.

i. When lift is ascending at uniform velocity neither length nor acceleration changes, thus, the period remains the same.

ii. When the lift is ascending at an acceleration a m/s2 the resultant acceleration becomes a+g, and the period decreases.

iii. When the lift cable snaps, the acceleration becomes 0 and the pendulum does not oscillate.