What is energy?

•We need energy to make things work.

•Energy is the ability to work.

Different forms of energy * Heat energy * Potential energy

*Kinetic energy * Electrical energy

* Light energy * Sound energy

*Chemical energy

Energy conversion When we turn on the light… Electrical light energy & heat energy.

When we turn on the radio…Electrical energy sound energy.

When we wind up a toy car…Kinetic energy potential energy

When we run…Chemical energy kinetic energy

Clear:•For the past

•Burn coal

•Dirty

•Now

•Use electricity

•More clean

Convenient:For the past:Buy oil Put it into the oil lamplight a match Waitlight comes out

Now:Put the plugs into thesocketPress the switchimmediatelylight

Pollution from electricity

•Air pollution:•Sulphur dioxid

e-----acid rain---kill the trees

•carbon dioxide----Greenhouse effect

The amount of that energy people use

• The diagram shows us, we had use a lot of energy.

• Once some kind of energy are used up, the energy they contain will gone forever.

• So we have to save energy.

Annual energy consumption per person, billions of joules

0 100 200 300 400

India

Brazil

China

Japan

Britain

Germany

Russia

Canda

U.S.

Summary

• Energy is very important in our daily lives. When we product some kind of energy, we will make some pollution.

• If we use the energy misapply, the energy will use up one day.

• So we have to save energy and save our Earth.

Group membersChan Shui Chi Lo Kwun Yi

Cheung Ka Yan Tong Sin Yi

Leung Wai Ching Wong Nap Pui

Lam Tsz Ling

~The End~