Question

a girl has a pendulum which she has made by tying a stone to thread . Its time period is one second. How can she reduce time period of pendulum

Answer 1

Since the pendulum is made by tying a stone to the thread, the time reduction can take place by decreasing the length of the thread.

This happens because the period of the pendulum is proportional to the square root of its range.

Thus, a girl can just cut off the length of the swing, and she is good to go.