Final answer:
In hydroelectric energy generation, the potential energy of water stored behind a dam is converted to kinetic energy as it flows downward, which is then converted to mechanical energy as it turns turbines, and ultimately transformed into electrical energy by a generator.
Step-by-step explanation:
The energy transformations involved in generating hydroelectric energy when water is released from a dam are as follows:
- As lake water flows downward through tunnels, the potential energy of the water is transformed into kinetic energy.
- When the flowing water turns turbines, the kinetic energy of the water is transferred to the turbines, causing them to rotate. This kinetic energy is partially converted into mechanical energy of the spinning turbines.
- As the turbines spin, they drive the generator, which results in the conversion of mechanical energy into electrical energy. This electricity is then ready to be distributed across the power grid.
The environment that is doing work on the system, which in this case is the water, is gravity acting on the mass of the water. The water's pressure head, due to the height of water above the turbines, helps create the force necessary to move the turbines. If a dam has water 100 m deep behind it and 10,000 kg of water exited the dam at 2.0 m/s, we can calculate the energy generated using the concept of gravitational potential energy and kinetic energy provided by the movement of water.