What transformations of one type of energy into another occur: a) when a waterfall falls

What transformations of one type of energy into another occur: a) when a waterfall falls; b) when throwing the ball vertically upwards; c) when tightening the spring of a mechanical watch; d) by the example of a door spring.

When a waterfall falls, its potential energy goes into kinetic.
When throwing the ball vertically upwards, its kinetic energy goes into potential.
The potential energy of the spring passes into the kinetic energy of the moving arrows.
The potential energy of a stretched spring translates into the energy of movement of the door.

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