Hydroelectric energy is based on the of water being converted to as water falls and pushes against the turbine.
kinetic; potential
potential; kinetic
chemical; electric
mechanical; chemical

Hydroelectric energy is based on the potential energy of water being converted to kinetic energy as water falls and pushes against the turbine.

Explanation:

Initially, the water is at the top of its trajectory. At this moment the water possesses gravitational potential energy due to its height relative to the ground. The gravitational potential energy is given by:

where m is the mass of the water, g is the gravitational acceleration, and h is the heigth of the water relative to the ground.

As the water falls, the height h increases, and the gravitational potential energy decreases, being converted into kinetic energy, since the water gains speed. In fact, the kinetic energy is given by

where v is the water's speed. At the bottom of its trajectory, all the gravitational potential energy has been converted into kinetic energy: now the water flows through the turbines, pushing them and making them rotating, and this energy will be converted into electrical energy.

prndulum needs thread, weight clock to time swings