Types of Energy

Gravitational Energy

This is the energy added to an object to raise it to a given height on the earth's surface.

$E = mgh$

• $m$ is the mass of the object

• $g$ is the acceleration due to gravity

• $h$ is the height of the object

If we measure the mass in kilograms, the acceleration in meters per second squared, and the height in meters, our energy will be in units of joules.

Kinetic Energy

This is the energy added to a moving object like a baseball or an automobile for it to have a given velocity.

$E = \frac{1}{2}mv^{2}$

• $m$ is the mass of the object

• $v$ is the velocity of the object

If we measure the mass in kilograms and the velocity in meters per second, the energy will be in joules.

Thermal Energy

$E = mc\Delta T$

This is the energy to raise the temperature of a substance.

• $m$ is the mass of the material

• $c$ is the specific heat capacity of the material

• $\Delta T$ is the rise in the temperature of the material

Chemical Energy

This is the product of the amount of a substance multiplied by its energy density.

Nuclear Energy

$E = mc^2$

This is the energy that can be released by splitting or fusing the nuclei of atoms. In a fission reaction, the two nuclei weigh less than the original nuclei and the difference in masses is released as energy.