Question

A child is stationary on a swing.
The child is given a push by a parent and the child starts swinging.
The parent stops pushing the child.
Figure 2 shows how the kinetic energy stored in the child varies over the first few swings.
Figure 2
Explain the energy changes during the first few swings.

Answer 1

Answer:

    When the parent pushes the child the main energy changes are between kinetic energy and potential energy. The details on how this energies change simultaneously is answered below.

Explanation:

Before the child is given a push by the parent, he is stationary. When the child is given a push by the parent, the child will swing and reach a certain height (The maximum height the boy can reach ) were he has full potential energy. Under the influnce of gravity the child will swing backwards and at the very bottom of the swing it posses its maximum kinetic energy. A diagram is attached for better understanding.