Warm-up Energy Reading What are the different types of energy? How is energy transferred or transformed? Lesson Essential Question

Energy CANNOT be created or destroyed… The law of conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in the system is a constant. PE + KE = 0

Energy Classification There are two main forms of energy, kinetic energy (motion) and potential energy (position). To further classify energy, these forms are sometimes further described as thermal (heat), elastic, electromagnetic (light, electrical, magnetic), gravitational, chemical (food), and nuclear energy.

Energy can be transferred and transformed Energy Transfer: Energy can be transferred from one location to another The two ways that energy can be transferred are by doing work and heat transfer. When work is done on an object, it results in a change in the object's motion Energy is often defined as the ability to do work.

Energy can be transferred and transformed Heat is given off when an object's thermal energy is transferred. Thermal energy can be transferred in three ways: by conduction, by convection, and by radiation.

Conduction Conduction is the transfer of energy from one molecule to another.

Convection Convection is the movement of heat by a liquid such as water or a gas such as air.

Radiation i s the transfer of heat by electromagnetic waves. When infrared rays strike a material, the molecules in that material move faster.

Energy Transformation Energy in a system may be transformed so that it resides in a different state. Energy in many states may be used to do many varieties of physical work. Energy may be used in natural processes or machines, or else to provide some service to society (such as heat, light, or motion).

Examples… An internal combustion engine converts the potential chemical energy in gasoline and oxygen into heat, which is then transformed into the propulsive energy (kinetic energy that moves a vehicle.)

Example A solar cell converts solar radiation into electrical energy that can then be used to light a bulb or power a computer.

Example of energy transformation

Type of EnergyDescription and Examples Kinetic Gravitational Elastic Electric Magnetic Mechanical Heat Nuclear Light Chemical