Energy Transformations

Energy Transformations • Several forms of energy have been defined. • Each kind can be changed into other kinds

Chemical Energy • energy stored in bonds that hold atoms together as molecules. Food Fuel

Nuclear Energy • energy stored in the nucleus of an atom; released when nuclei split apart or join together Nuclear Fusion Nuclear Fission Nuclear Power Plants Fusion in the sun

Gravitational Energy • energy stored in an object as the result of its height Pendulum Roller coaster car at top of hill

Elastic Potential Energy • energy stored in elastic materials as the result of their stretching or compressing. Stretched Rubber Band Compressed spring

Electrical Energy Energy of moving electrical charges Electrical charges moving through wire Lightning

Radiant Energy Microwaves • Energy that travels as electromagnetic waves. Xrays “David Banner belted by gamma rays turns into The Hulk”

Sound Energy • Energy given off by vibrating objects; energy we can hear

Mechanical Energy • Energy of motion used to do work Wind Flowing water Machines Your body when you move

Thermal Energy • Thermal energy is the energy an object has due to the motion of its molecules. The faster the molecules in an object move, the more thermal energy the object has. The lava flowing from this volcano has a large amount of thermal energy.

Forms of Energy

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

Mechanical Energy  Electrical Energy Mechanical energy of moving water can be transformed into electrical energy

A toaster transforms electrical energy into thermal energy to toast your bread Electrical Energy Thermal Energy

Your body transforms the chemical energy in your food to mechanical energy you need to move your muscles. Chemical EnergyMechanical Energy

Chemical energy in food is also transformed to the thermal energy your body uses to maintain temperature. Chemical Energy Thermal Energy

Many common devices transform electrical energy into other forms. Thinks about the following devices in terms of energy transformations. ceiling fan digital clock hair dryer For each device, describe which form or forms of energy the electrical energy becomes. Energy TransformationsYou Try It…

Electrical  Mechanical

Electrical  Radiant (Light)

Electrical ThermalElectrical  Mechanical

Green plants change radiant energy (light) to chemical energy. Radiant Energy  Chemical Energy

Burning fuels changes chemical energy into mechanical energy Chemical Energy  Mechanical Energy

A lightbulb changes electrical energy to light energy Electrical Energy  Light Energy

In any energy transformation, some energy changes to heat. • Energy can be changed from one form to another but it can never be created or destroyed. Conservation of Energy

Energy and Friction • A sliding hockey puck comes to rest because friction converts its kinetic energy into heat.

Einstein’s Theory of Relativity "It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing -- a somewhat unfamiliar conception for the average mind. Furthermore, the equation E is equal to m c-squared, in which energy is put equal to mass, multiplied by the square of the velocity of light, showed that very small amounts of mass may be converted into a very large amount of energy and vice versa. The mass and energy were in fact equivalent, according to the formula mentioned above. This was demonstrated by Cockcroft and Walton in 1932, experimentally." Videos on Relativity Energy and Matter E = mc2

Energy Transformations