Question

complete these sentences.
if a bouncing ball has a total energy of 20 j and a kinetic energy of 5 j, the ball’s potential energy is j.
if the kinetic energy of the ball decreases, then the potential energy will .
5
10
15
20

Explanation:

Step1: Calculate potential energy

The total energy \(E\) of an object is the sum of its kinetic energy \(K\) and potential energy \(U\), i.e., \(E = K+U\). Given \(E = 20\space J\) and \(K = 5\space J\), we can find \(U\) by rearranging the formula: \(U=E - K\).

$$U=20 - 5=15\space J$$

Step2: Analyze energy transformation

According to the law of conservation of mechanical energy (assuming no non - conservative forces like air resistance act significantly in the short - term bouncing process), the total mechanical energy \(E = K + U\) is constant. If \(K\) decreases (\(\Delta K<0\)), then \(U\) must increase (\(\Delta U>0\)) to keep \(E\) constant.

Answer:

The ball's potential energy is \(15\space J\). If the kinetic energy of the ball decreases, then the potential energy will increase.