1. Energy

2. What is energy? The capacity or the power to do work
It is associated with any change
DON’T confuse it with force (to push or pull or twist something)

3. Conservation of energy
You cannot create energy out of nowhere
Energy is simply transferred from one form to another
Potential energy – stored energy (waiting to be used)
Kinetic energy – energy of motion (already being used)

4. A Roller Coaster A roller coaster speeds along its track
It has kinetic energy because it is moving

5. A Roller Coaster
As it slows to a stop at the top of a hill, it has potential energy because of where it is
It has the potential to move because it is above the ground and has somewhere to go

6. Potential Energy of Ramps Experiment

7. Types of energy Kinetic – energy involving movement
Nuclear – energy of the particles inside an atomic nucleus
Sound – energy involving vibrations in the air that create noise
Gravitational – energy involving the ability to fall downwards
Light – energy involving the production of visible light
Elastic – energy involving a stretched object with the ability to return to its natural shape
Electrical – energy involving the movement of electrons
Chemical – energy involving chemical reactions
Heat – energy involving the movement of the particles within a substance

8. What is Kinetic Energy? The bowling ball has kinetic energy.
Energy due to a object’s motion
The bowling ball has kinetic energy.
When the ball strikes the pins, kinetic energy is transferred to the pins!

9. Examples of Kinetic Energy

10. Gravitational Energy
Energy an object or substance has because of its position
Anything “up high”

11. What is Electrical Energy?
Energy caused by the movement of electrons
Easily transported through power lines and converted into other forms of energy

12. What is Chemical Energy?
Energy that is available for release from chemical reactions.
The chemical bonds in a matchstick store energy that is transformed into thermal energy when the match is struck.

13. Examples of Chemical Energy

14. What is Heat Energy?
The heat energy of an object determines how active its atoms are.
A hot object is one whose atoms and molecules are excited and show rapid movement.
A cooler object's molecules and atoms will show less movement.

15. Types of Energy – Road Runner Clips

16. Classes of Energy
POTENTIAL
KINETIC
Energy of motion
Stored energy ? ?

17. Classes of Energy POTENTIAL KINETIC Energy of motion Stored energy
Kinetic, Electrical, Sound, Light, Heat
Gravitational, Nuclear, Chemical, Elastic

18. Activity
Design a poster or collage on your iPads of the 9 types of energy
For each type of energy:
Find 3 examples
Identify whether it is potential energy or kinetic energy
Draw or find 1 or more pictures showing the energy

19. A battery powering a light bulb
Discussion Questions
Does the bulb have energy? What evidence is there of this?
Where does that energy come from?
What happens to that energy?
If the bulb has energy what happens to it?

20. Solar cells powering a fan
Discussion Questions
Does the bulb have energy? What evidence is there of this?
Where does that energy come from?
What happens to that energy?
If the bulb has energy what happens to it?

21. An operating electric heater
Discussion Questions
Does the electric heater have energy?
Where does that energy come from?
What happens to that energy?
If the electric heater got energy from the power station, where did the power station get energy from? [If they suggest from the hot steam then keep asking where does this energy come from – is there a point where energy gets created?]

22. Rubber band powered toys
Discussion Questions
Does the toy have energy just as it starts moving?
Where does that energy come from?
If the toy has energy, how is that energy transformed? What happens to the energy after the toy has stopped?

23. Spring-powered toys Discussion Questions
Does the jumping toy have energy before it is released?
Where does that energy come from?
If the toy has energy, what happens to that energy? What happens to the energy after the toy has stopped?

24. Energy Transfers and Transformations
All things possess energy even if they are not moving
Energy cannot be created or destroyed – the amount of energy in the universe is always the same
Law of Conservation of Energy
Energy can be stored (potential energy)
Energy can be transferred to another object
From a cricket bat to a ball
Energy can be transformed into a different form
From electrical energy to sound energy

25. Activity Complete the following table in your exercise books: Object
What to do to release stored energy
Potential energy is usefully transformed into…
Torch battery
Switch it on
Electrical energy, light energy
Chocolate
Petrol
Dynamite
Olympic diver on platform
Match
Stretched elastic band

26. Activity

27. Activity
Match the following scenarios/objects to the appropriate energy transformation sequence
Object/Scenario
Transformations
Lamp
Electrical → heat
Door bell
Chemical → heat
Microwave
Electrical →sound
Photosynthesis
Chemical → heat and mechanical
Gas stove
Light → electrical
Solar battery
Electrical →heat and light
Car
Light →chemical

28. Activity
Identify the Energy Transformations or Transfers in the following examples:

29. Energy Changes Prac

30. Wasted energy
In energy transfers and transformations, most of the energy is converted is useful
However, some of the conversions are not useful and wastes the energy
Appliance
Useful energy conversion
Wasted energy
Microwave
Electrical to heat
Light, sound, heating anything other than the food
Television
Electrical to light and sound
Heat
Hair dryer
Electrical to heat and kinetic (moving the air)
Sound
Lightbulb
Electrical to light
Heat, sound

32. Efficiency
The energy efficiency of an object is a measure of it’s ability to provide useful energy
This is usually expressed as a percentage

34. Bouncing Ball Prac