Hydroelectric dams make use of the differences in water levels to generate electricity. Which of the following shows the energy conversion in a dam? A. Gravitational potential energy \(\rightarrow\) Kinetic energy \(\rightarrow\) Electrical energy B. Electrical energy \(\rightarrow\) Heat energy \(\rightarrow\) Electrical energy

Gravitational potential energy is the energy stored in an object due to its position in a gravitational field. In the context of a hydroelectric dam, this type of energy is stored in the water held at a higher elevation. The formula to calculate gravitational potential energy is given by: \(PE = mgh\), where:

• \(PE\) is the gravitational potential energy.
• \(m\) is the mass of the water.
• \(g\) is the acceleration due to gravity (approximately 9.8 m/s²).
• \(h\) is the height or elevation of the water.

When the water is released from the dam, it flows down due to gravity. This process converts the gravitational potential energy into another form of energy.

As water flows down from the height of the dam, its gravitational potential energy is transformed into kinetic energy. Kinetic energy is the energy of motion. The formula for calculating kinetic energy is: \(KE = \frac{1}{2}mv^2\), where:

• \(KE\) is the kinetic energy.
• \(m\) is the mass of the water.
• \(v\) is the velocity (speed) of the water as it flows down.

Because the water gains speed as it falls, its kinetic energy increases. This flowing water is then directed towards turbines. The kinetic energy of the moving water is what drives these turbines, making them spin.

The spinning turbines are connected to generators, which convert mechanical energy (from the spinning motion) into electrical energy. This is the final step in the energy conversion process within a hydroelectric dam. The generators use electromagnetic induction to produce electricity. This principle is based on Faraday's law, which states that a changing magnetic field within a coil of wire induces an electric current.

• In simple terms, the mechanical motion in the turbines generates an electric current in the generator.

The electrical energy produced can then be transmitted through power lines to homes, businesses, and other places where it is needed. This shows the complete process of energy conversion: starting from gravitational potential energy, transforming into kinetic energy, and finally being converted into electrical energy.