3. WHAT IS ENERGY?
• Energy is the power that allowsus to do things.
• Usuallywecannot see it or touchit but it isall
around us.
• Energy cantake form of light,sound, heat or
movement. It canpower machines.
• It canchange from oneform to another too.
For example,whenyouturn on a light,the
electricitytransforms into lightand thermalenergy.
8. FORMS OF ENERGY
• LIGHT ENERGY
• SOUND ENERGY
• THERMAL ENERGY
• ELECTRICAL ENERGY
• CHEMICALENERGY
• KINETICENERGY
9. LIGHT ENERGY
• Most of the lighton Earth comes from the Sun. Lightsources
canbe natural,such as thestars, or artifical,suchas light
bulbs and torches.
• Light travels very fast. It is the fastest form ofenergy. It
travels at 300.000 kilometresper second.
• Even though lightlooks white,it is made up of seven
different colours.
• Light alwaystravels in astraight line.
https://goo.gl/images/UjhTEh
10. SOUND ENERGY
• Sound is a vibration and can travel in any direction from the
source.Vibrating objects transmit these vibrations into the
air.
• Sound can travel veryquickly, but no as fast as light.
• Sound can travel through gases, liquids and solids, evenif
they are opaque. Soundcannot travel through a vacuum
because in a vacuum thereare noparticles to vibrate.
https://goo.gl/images/8hcpcE
https://goo.gl/images/M7gn78
11. CHEMICAL ENERGY
• Chemical energyis released whena chemical
reaction occurs.Whena car burns petrol, a chemical
reactionoccursbetween the petrol and oxygen.This
chemicalenergy is then transformed intokinetic
energy.
•Batteries and food are sources of chemicalenergy too.
https://goo.gl/images/X8jKk4
12. KINETIC ENERGY
• Allmoving things,have kineticenergy. This energyis
produced throughmotion or movement.The heavier
an object is, and the faster it moves, the more kinetic
energy it has.
•Examplesof kineticenergy includea moving car, a
windsurferor your bikewhenit is inmovement. Living
things have kineticenergy too.
https://goo.gl/images/QBaPca
13. ELECTRICAL ENERGY
• Electricalenergyis used to power machines.Wecan
transform it into light,sound, heatand movement.
•The energy to generate electricitycomes from
different sources. A lot of our electricityis still
produced by burning fossil fuels.Electricitycanalso be
generated usingenergy from sunlight,windand water.
https://goo.gl/images/aNqAbC
14. THERMAL ENERGY
• Thermal energy flows from a warm substance to a
cooler substance. This fllowofthermal energy is called
heat. A change in the thermal energyof a substance
canalso make the substance changestate.
•The Sunis the mainsource of heaton Earth.Other
sources includefossil fuels, whichweuse to warm our
houses and cook ourfood. These fuels comeform
underthe ground and includecoal,oilandgas.
https://goo.gl/images/rsgyNq