Hydroelectric dams work by blocking the path of a water source to create an area with water held back by the dam. The dam can then be opened to allow water to be released. The energy from the moving water is used and transformed into electrical energy. What type of energy does a hydroelectric dam capture as the water passes through?
a
Sound Energy
b
Nuclear Energy
c
Mechanical Energy
d
Light Energy
c
Mechanical Energy
are you correct
Yes, I am correct. Hydroelectric dams capture mechanical energy as the moving water passes through and use it to generate electrical energy.
The total amount of energy in the universe never changes, but the availability of each different type of energy to do work can change tremendously. What best explains this change in available energy?
a
Energy can only be transferred as heat.
b
Energy is always converted with 100 percent efficiency.
c
Energy can only be created through nuclear reactions.
d
Energy is regularly changing from one form into another.
d
Energy is regularly changing from one form into another.
are you sure?
Yes, I am sure. Energy is regularly changing from one form into another. This is known as the principle of energy conversion or the conservation of energy. Although the total amount of energy in the universe remains constant, it can change from one form to another, such as from kinetic energy to potential energy or from electrical energy to thermal energy.
A mixture of gases is heated and rises to the top of its container. Which statement best explains this result?
a
Heated gases will have increased kinetic energy and increased density.
b
Heated gases will have increased kinetic energy and decreased density.
c
Heated gases will have decreased kinetic energy and decreased density.
d
Heated gases will have decreased kinetic energy and increased density.
b
Heated gases will have increased kinetic energy and decreased density.