Hydroelectric power stations generate electricity by using the force of water that falls into the turbines and spins the shaft. By rotating the shaft of the turbine, the potential energy of water is converted into ________ energy.

kinetic

The correct answer is option 4. kinetic.

Hydroelectric power stations utilize the gravitational potential energy of water stored at higher elevations. This potential energy is a result of the water being lifted or raised to a certain height above the turbines in the power station. When this water is released, it flows downhill under the influence of gravity.

As the water flows down through pipes or channels, it gains kinetic energy due to its movement. This kinetic energy is essentially the energy of motion. When the water reaches the turbines at the base of the dam or power station, its kinetic energy is used to rotate the turbine blades. The rotating turbine shaft is connected to a generator, which converts the mechanical energy of the rotating shaft into electrical energy.

Therefore, the potential energy of the water stored in the reservoir is converted into kinetic energy as the water flows downhill and spins the turbines. Finally, this kinetic energy is converted into electrical energy by the generators.