Question

A 26.3-kg child jumps off a diving board 1.5m above the surface of a pool. If all of the child’s potential energy is converted into kinetic energy, how fast is the child going when he hits the water?

Answer 1

$$\dfrac 12mv^2=mgh,\\\space\\ v=\sqrt{2gh}=\sqrt{2·9.8·1.5}=5.42\text{ m/s}.$$