question_answer

A child swinging on a swing in sitting position, stands up, then the time period of the swing will  [AIEEE 2002]

A)  increase                       

B)  decrease

C)  remain same

D)                                                          increase if the child is long and decrease if the child is short                                             

Correct Answer: B

Solution :

[b]

As the child stands up, the effective length of pendulum decreases due to the reason that the centre of gravity rises up. Hence,

For time period, , T will decrease.