Forms of Energy

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

1. Which type of energy is emitted by the Sun, lamps
   and stars?
2. Which type of energy is stored in the nuclei of
   atoms?
3. Which type of energy is stored in food, fuels and
   batteries?
4. Which type of energy is possessed by flowing
   electrons?
5. 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

1. What happens to the gravitational energy of an
   object as it gets higher in a gravitational
   field?
2. What happens to the kinetic energy of an object
   as it moves faster?
3. Which type of energy are kettles, irons and
   Bunsen burners designed to produce?
4. 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

1. Name three devices that use electrical energy.
2. Why is electrical energy so useful?
3. What is the main energy transfer for a catapult?
4. What is the main energy transfer for a coal fire?
5. What is the main energy transfer for a solar
   cell?
6. 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

1. What happens to wasted energy?
2. In which two forms is energy usually wasted?
3. In what form do all electrical devices waste
   energy?
4. If you can hear a device that is not supposed to
   make a noise, in what form is energy being
   wasted?
5. In what forms does a hairdryer waste energy?
6. 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
Electrical to sound
Catapult
Electrical to heat
Kettle
Elastic to kinetic
Wind turbine
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.