1. Forms of Energy
Energy types
Energy transfers
Wasted energy
Joules

2. Exercise 1: Types of Energy 1
Many objects EMIT(GIVE OUT) light. This is a type of electromagnetic radiation.
Kinetic Energy
All sounds are caused by VIBRATIONS. The LOUDER a sound, the MORE energy it has.
Sound Energy
This is the energy possessed by an object due to its MOVEMENT. The FASTER an object moves, the MORE energy it has.
Light Energy

3. Exercise 2: Types of Energy 2
This is the energy stored in the NUCLEI of atoms.
Thermal Energy
This is the energy an object possesses due to it being STRETCHED or SQUASHED.
Nuclear Energy
The HOTTER an object is, the MORE of this energy it has.
Elastic

4. Exercise 3: Types of Energy 3
This is the energy possessed by FLOWING ELECTRONS (ELECTRICAL CURRENT).
Electrical Energy
The is the energy an object possesses due to its position in a GRAVITATIONAL FIELD. The HIGHER an object is in the field, the MORE of this energy it has.
Chemical Energy
This is the energy stored in FUELS, FOOD and BATTERIES. It is released through CHEMICAL REACTIONS.
Gravitational Energy

5. Exercise 4: Forms of Energy
Which type of energy is emitted by the Sun, lamps and stars?
Which type of energy is stored in the nuclei of atoms?
Which type of energy is stored in food, fuels and batteries?
Which type of energy is possessed by flowing electrons?
Which type of energy is possessed by an object that is being stretched or compressed ?
Light.
Nuclear.
Chemical.
Electrical.
Elastic.

6. Exercise 5: Forms of Energy
What happens to the gravitational energy of an object as it gets higher in a gravitational field?
What happens to the kinetic energy of an object as it moves faster?
Which type of energy are kettles, irons and Bunsen burners designed to produce?
Which sounds have the most energy, loud or quiet?
It increases.
It increases.
Heat.
The louder the sound, the more energy it has.

7. Exercise 6: Link the Diagram with the Energy
Sound
Chemical
Light
Kinetic

8. Energy Changes
Energy CAN NOT be CREATED or DESTROYED; it can only be CHANGED IN FORM.
Many devices convert energy from one form to another. ELECTRICITY is a VERY USEFUL form of energy because it is VERY EASY to convert from one form to another.
What is the energy transfer for a lamp?
Start energy?
Electrical energy
End energy?
Light energy

9. Exercise 7: Transfers Name three devices that use electrical energy.
Why is electrical energy so useful?
What is the main energy transfer for a catapult?
What is the main energy transfer for a coal fire?
What is the main energy transfer for a solar cell?
What is the main energy transfer for a television?
TV, radio, cooker, iron, microwave, freezer.
It is easy to transfer from one form to another.
Elastic to kinetic.
Chemical to heat.
Light to electrical.
Electrical to light and sound.

10. Wasted Energy
Whenever an energy transfer occurs some energy is ALWAYS WASTED. Where does this energy go to?
It SPREADS OUT and is LOST to the SURROUNDINGS. It is very hard to REUSE. This is why we should be mindful not to waste energy needlessly.
What is the wasted energy for an electrical lamp?
A lamp is designed to change electrical energy into light energy.
Some energy is wasted in the form of HEAT though. In fact, ALL ELECTRICAL devices WASTE ENERGY in the form of HEAT.
If you could hear the lamp buzzing then it would be wasting energy in the form of SOUND.

11. Exercise 8: Wasted Energy
What happens to wasted energy?
In which two forms is energy usually wasted?
In what form do all electrical devices waste energy?
If you can hear a device that is not supposed to make a noise, in what form is energy being wasted?
In what forms does a hairdryer waste energy?
In what form does a coal fire waste energy?
It spreads out into the surroundings and is harder to reuse.
Heat and sound.
Heat.
Sound.
Heat and sound.
Light energy.

12. Exercise 9: Link the Device with the Main Energy Change
Microphone
Light to electrical
Loudspeaker
Sound to electrical
Catapult
Electrical to sound
Kettle
Electrical to heat
Wind turbine
Elastic to kinetic
Solar cell
Kinetic to electrical

13. Exercise 10: Units of Energy
What are the units of energy?
JOULES (J)
A radio converts 300J of electrical energy into 120J of sound energy.
a) In what form is energy wasted by the radio?
b) What happens to this wasted energy?
c) How much energy is wasted?
d) In what other form is energy usually wasted by devices?
Heat.
Spreads out into surroundings and is harder to reuse.
180J.
Sound.

14. Exercise 11: A Car Engine
A car engine uses the fuel petrol. The car converts 400J of the energy stored in petrol into 100J of kinetic energy.
a) What energy is stored in petrol?
b) In what forms is energy wasted by a car engine?
c) How much energy is wasted by the car engine?
d) What percentage of useful energy is transferred by the engine?
Chemical.
Heat and sound.
300J.
25%.