Energy

What is energy? Energy is the ability to do work or cause change. Work is done when a force moves an object through a distance. Work is the transfer of energy. (The object that work is being done on gains energy) Both energy and work are measured in joules (J). Example: The wind moving a leaf causes change, therefore, the wind has Energy.

Which object is gaining energy?

What is the ability to do work called?

There are 2 kinds of energy… Kinetic energy= the energy of motion Potential energy= stored energy

Kinetic Energy The amount of kinetic energy an object has depends on its mass and velocity. Velocity=how fast an object moves The more work you do to get an object moving, the more energy you give that object.

Which has more kinetic energy when traveling at the same velocity?

A bowling ball would have more kinetic energy than a golf ball when traveling at the same velocity, because you would have to do more work to get the ball moving. Kinetic energy increases when velocity increases.

Checkpoint What is kinetic energy?

Potential Energy This type of energy has the potential to do work. There are 2 types: Elastic and Gravitational.

Elastic Potential Energy Elastic potential energy is associated with objects that can be stretched or compressed. An archer gives potential energy to a bow by pulling it back. This stored energy can send an arrow whistling to its target.

Gravitational Potential Energy Gravitational potential energy depends on height. This energy is equal to the work done to lift it. The greater the weight of the object or the greater the height its lifted, the greater its gravitational potential energy.

How could this man increase his gravitational potential energy?

Different forms of Energy Mechanical Thermal Chemical Electrical Electromagnetic Nuclear

Mechanical Energy Energy associated with the motion or position of an object. Can occur as potential or kinetic. Examples: frog leaping through the air or school bus you ride in.

Thermal Energy Is the measure of the energy of the particles in an object. (atoms and molecules which make up all matter) These particles have both kinetic and potential energy due to their arrangement and motion. When thermal energy increases, its particles move faster making it feel warm to the touch. (Ice cream melts when thermal energy increases.)

Chemical Energy Some chemical compounds such as chocolate, wood and wax store chemical energy. Chemical energy is potential energy stored in chemical bonds that hold chemical compounds together. Chemical energy is stored in the foods you eat, the match you use to light a candle and in the cells of your body.

Electrical Energy When you receive a shock from a metal doorknob you experience electrical energy. Moving electric charges produce electricity and they carry electrical energy. We rely on batteries and power lines to run electrical devices such as radios, lights and computers.

Electromagnetic Energy Radiant energy is the energy that travels in waves. These waves have electrical properties and magnetic properties. Examples: light we see each day, ultraviolet radiation, microwaves and infrared radiation.

Nuclear Energy A type of potential energy. Stored in the nucleus of an atom and released during nuclear reactions. Nuclear power plants use fission reactions to produce electricity. (nucleus splits apart) The sun and other stars create energy through nuclear fusion. (nuclei join together)

Questions Are energy and work the same thing? How are kinetic and potential energy different? List the forms of energy and give an example of each.