Question

How long does it take a child on a swing to complete one swing if her center of gravity is 4.00 m

below the pivot? Explain your answer. (

Answer 1

We can find the period of one swing of a child from the definition of the period of pendulum:

$$T=2\pi\sqrt{\dfrac{l}{g}}=2\pi\sqrt{\dfrac{4\ m}{9.8\ \dfrac{m}{s^2}}}=4.01\ s.$$