A 72 kg swimmer jumps into a pool from a diving board 3.25 m above the water. Use energy conservation to find his speed just as he hits the water if he jumps straight up (but just beyond the board!) at 2.5 m/s. A. 10.5 m/s B. 5.7 m/s C. 7.4 m/s D. 8.4 m/s

Respuesta :

Answer:

8.06 m/s

Explanation:

It is given that,

Mass of a swimmer, m = 72 kg

He jumps from a diving board 3.25 m above the water.

We need to find the speed just as he hits the water if he jumps straight up. Using the conservation of energy to fin it as follows :

[tex]mgh=\dfrac{1}{2}mv^2\\\\v=\sqrt{2gh} \\\\v=\sqrt{2\times 10\times 3.25}\\\\ v=8.06\ m/s[/tex]

So, the required speed is 8.06 m/s.