<em><u>throwing a ball up initially has a lot of kinetic energy because it is moving upwards ( kinetic energy is energy which a body possesses by virtue of being in motion.) this all then get converted to gravitational potential energy, and for a moment it is stationary before it begins to fall again. by the time it has returned again, all the gravitational potential energy has turned back into kinetic.</u></em>
It’s solved by using a pretty standard formula for efficiency.
A human hair is approximately 50 μm = 5 × 10⁻⁵ m in diameter
It brings cold water from the bottom of the ocean.