Energy: An overview

Energy Forms

Most forms of energy fall into one of two categories:

• Kinetic energy (Motion) Ex. train speeding down a track, a jumping frog, you’re walking

• Potential energy (stored) Ex. A stretched rubber band has potential energy. When you release the rubber band, it jumps away from your hand. The rubber band now has kinetic energy

Multiple Choice

Energy of motion us called .............

• Kinetic Energy

• Potential Energy

1) Mechanical energy

Is the sum of potential energy and kinetic energy.

It is associated with the motion and position of an object.

2) Electrical energy

Is energy associated with electric charges.

3) Thermal Energy

Is the kinetic energy of all the atoms and molecules in an object.

The more energy the atoms and molecules have, the faster they move.

If the particles in an object start to move faster, the object will become warmer.

Multiple Choice

Thermal Energy is considered as ...............

• Kinetic energy

• Potential energy

Multiple Choice

If the particles in an object start to move faster, the object will become .........

• Cooler

• Closer

• Warmer

Multiple Choice

The sum( total) of kinetic energy and potential energy is called .........

• Electrical energy

• Thermal energy

• Mechanical energy

4) Chemical Energy

Is energy stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place.

Examples:

➢Food: When you move your legs and arms during walking, your body converts chemical energy stored in food into mechanical energy.

➢ Fossil fuels contain energy stored in the molecules of chemical compounds.

Multiple Choice

................is energy stored in the bonds of chemical compounds, like atoms and molecules.

• Chemical energy

• Thermal energy

• Atomic energy

Multiple Choice

Energy stored in food is ........ energy

• Electrical

• Kinetic

• Chemical

5) Nuclear Energy

Involves forces within atoms. The forces that hold nuclear particles together in the nucleus can store a huge amount of potential energy

Multiple Choice

Nuclear energy is a type of ....... energy

• Kinetic

• Potential

Energy Conversion

Energy can be converted, or changed, from one form to another.

Examples

In the fan’s motor

Electrical energy has been converted to mechanical energy.

In combustion,

chemical energy stored in the fuel is converted to thermal and electromagnetic energy. You feel the thermal energy as heat and see the electromagnetic energy as light.

Sources and Uses of Energy

•Renewable energy

•Nonrenewable energy

Renewable energy resources include:

Sun

Wind

Hydro-power : Moving water

Wood from trees

Geothermal: Heat that comes from deep within Earth

Nonrenewable energy resources include:

•Fossil fuels, such as coal, oil, and natural gas

• Nuclear energy.

Energy Use

Four uses of energy:

1. Industrial

2. transportation

3. residential

4. commercial

Developed nations tend to use more energy than developing nations