A 66.0 kg diver is on a diving board, which is 1.10 m above the water. He falls at a speed of 9.10 m/s. Calculate his kinetic energy as he hits the water.

I know KE is 1/2mv^2, but how can I find KE when height is involved?

You have the potential energy: mgh.

Set that potential energy equal to 1/2 m v^2

Thanks. :)

To calculate the kinetic energy of the diver as he hits the water, you need to consider the energy conversion from potential energy (due to the height) to kinetic energy (due to the speed).

The potential energy (PE) is given by the formula PE = mgh, where m is the mass (66.0 kg), g is the acceleration due to gravity (approximately 9.8 m/s^2), and h is the height (1.10 m).

In this case, the height is acting as potential energy, but since you are trying to find the kinetic energy (KE), you need to find the difference between the initial potential energy and the final kinetic energy. This difference is due to the energy conversion during the fall.

So, to calculate the kinetic energy of the diver, you need to subtract the potential energy from the initial total mechanical energy (consisting of potential energy and kinetic energy right before the diver falls):

Initial total mechanical energy = Potential energy + Kinetic energy before falling

The initial kinetic energy can be assumed to be zero since the diver is at rest on the diving board.

Thus, the initial total mechanical energy = PE + 0 = mgh

Now, you can calculate the potential energy: PE = (66.0 kg) × (9.8 m/s^2) × (1.10 m)

The kinetic energy (KE) will be equal to the initial total mechanical energy.

KE = Initial total mechanical energy = PE = mgh = (66.0 kg) × (9.8 m/s^2) × (1.10 m)

So, the kinetic energy of the diver as he hits the water is equal to the calculated value.