Energy

By: S. S.

Unit 4 - Objectives• The relationship between work and energy is that when work is done on an object, energy is

transferred to that object.• Kinetic energy is related to mass and speed because that is the formula to calculate an object’s

kinetic energy. Also, the kinetic energy of any moving object depends upon the object’s mass and velocity/speed.

• Potential energy is related to an object’s position because the higher an object, the higher its potential energy.

• This is a table that states the major forms of energy and how each is produced:

major forms of energy

Kinetic Energy

Potential Energy

Gravitational Potential Energy

Elastic Potential Energy

Mechanical Energy

Thermal Energy

Chemical Energy

Electrical Energy

Electromagnetic Energy

Nuclear Energy

how the energy is produced

the object’s mass and velocity

energy that is stored as a result of position or shape

the object’s mass and acceleration due to gravity

an object being stretched or compressed

energy associated with the motion and position of everyday objects (Potential + Kinetic Energy)

the total Potential Energy and Kinetic Energy of microscopic particles in an object

energy stored in chemical bonds

energy associated with electric charges

a form of energy that travels through space in the form of waves

energy stored in atoms

Unit 4-2 Objectives • When energy is converted from one form to another , the total energy remains

unchanged. This is called the law of conservation of energy. Energy can be converted from one form to another, but the energy that is present at the beginning of a process is the same as the amount of energy at the end of the process.

• The law of conservation states that energy cannot be created or destroyed. For example, if you are roller skating and you stop skating, you will eventually stop moving. When you are skating you have kinetic energy, but when you stop skating the kinetic energy goes between the friction in the wheels and the ground. The work done by friction changes the kinetic energy to thermal energy.

• Energy is conserved in conversions between kinetic energy and potential energy because the gravitational potential energy of an object is converted to kinetic energy of motion as the object falls.

• The relationship between energy and mass is that the more mass, the higher the kinetic energy because the formula for kinetic energy is ½ mass x velocity squared.

Unit 4-3 Objectives

• Here are some of the major nonrenewable and renewable sources of energy. Some examples of nonrenewable resources are oil, gasoline, natural gas, coal, and uranium. Some examples of renewable resources are solar, wind, hydro electric, geothermal, biomass, and nuclear fusion.

• Here are the benefits and draw backs of different energy sources:

• Energy resources can be conserved if you try to use more renewable resources than nonrenewable resources.

energy sources benefits draw backs

hydroelectric •no pollution•low cost

•environmental impact (disrupts flow of fish and other wild life)•we don’t have enough rivers

solar •no pollution•low cost

•must have sun

geothermal •no pollution •not very accessible

biomass •cheap•renewable (easily grown)

•pollution

hydrogen fuel cell •no pollution •not as efficient

wind turbines •low cost•no pollution •renewable

•needs wind•takes up space

Ways to Conserve Energy

• don’t plug too many cords in one plug

• unplug things that you are not using

• turn off water and lights when you are not using them

• recycle

• use rechargeable things

• use windmills instead of fossil fuels

• ride a bike instead of driving a car