Final answer:
Hydroelectric power is the transformation of the potential energy in water into electricity. It is achieved by using dams to block the flow of river water and utilizing the kinetic energy of the water to turn turbines and generate electricity.
Step-by-step explanation:
Hydroelectric power is the transformation of the potential energy in water into electricity. This is achieved by using dams to block the flow of river water, creating a reservoir behind the dam. When the water is released, it flows down and turns the blades of turbines. The kinetic energy of the moving water is then converted into electricity by a generator.