Question

What is the speed of a 0.2 kg baseball if its kinetic energy is 40 j?

Answer 1

The kinetic energy of an object is given by:

`K=(1)/(2)mv^2`

where m is the mass of the object and v its speed. The ball in this problem has a mass of m=0.2 kg and a kinetic energy of K=40 J, so we can rearrange the previous equation to find its speed:

`v=\sqrt{(2K)/(m)} =\sqrt{(2 \cdot 40 J)/(0.2 kg)}=20 m/s`