Conversion and
conservation of energy
Arnold
Nana yaa
11/23/2023
1
Forms of energy
• Energy exists indifferent forms. They are
1. Sound energy
2. Chemical energy
3. Electrical energy
4. Heat energy
5. Light energy
6. Nuclear energy
7. Solar energy
8. Potential energy
9. Kinetic energy
11/23/2023
2
Sound energy
• Sound energy occurs when an
object vibrates. Noise, whether
within the human range of hearing
or not, is sound energy. Sonar,
ultrasonic (greater than 20
kilohertz) music, speech, and
environmental noise are all forms
of sound energy.
11/23/2023
3
Chemical energy
• Chemical energy is the energy of
chemical substances that is released
when they undergo a chemical
reaction and transform into other
substances. Some examples of
storage media of chemical energy
include batteries, food, gasoline, and
oxygen gas
11/23/2023
4
Electrical energy
• Electrical energy is energy derived as a
result of movement of electrons. When
used loosely, electrical energy refers to
energy that has been converted from
electric potential energy. This energy is
supplied by the combination of electric
current and electric potential that is
delivered by an electrical circuit
11/23/2023
5
Heat energy
• Heat energy is the result of the
movement of tiny particles called
atoms, molecules or ions in solids,
liquids and gases. Heat energy can be
transferred from one object to another.
The transfer or flow due to the difference
in temperature between the two objects is
called heat.
11/23/2023
6
Light energy
• Light energy is a kind of kinetic
energy with the ability to make
types of light visible to human
eyes. Light is defined as a form of
electromagnetic radiation emitted by
hot objects like lasers, bulbs, and the
sun. Light contains photons which are
minute packets of energy.
11/23/2023
7
Nuclear energy
• Nuclear power is the use of nuclear reactions
to produce electricity. Nuclear power can be
obtained from nuclear fission, nuclear decay
and nuclear fusion reactions. Presently, the
vast majority of electricity from nuclear
power is produced by nuclear fission of
uranium and plutonium in nuclear power
plants
11/23/2023
8
Solar energy
• Solar energy is radiant light and heat
from the Sun that is harnessed using
a range of ever-evolving
technologies such as solar heating,
photovoltaics, solar thermal energy,
solar architecture, molten salt power
plants and artificial photosynthesis.
11/23/2023
9
Potential energy
• Potential energy is the energy possessed by a body by
•
•
•
•
•
virtue of its position with respect to a reference level.
Objects raised above the Earth’s surface have potential
energy due to their position.
The formula for calculating potential energy is
P.E = m x g x h
Where m = the mass of the body
G= acceleration due to gravity
H = vertical height of a body from the ground.
11/23/2023
10
Kinetic energy
• Kinetic energy is the energy possessed by a body by
virtue of its motion. Any moving body possesses
kinetic energy. For example, a moving car possesses
kinetic energy and a falling fruit from a tree also
possesses kinetic energy
• The formula for calculating kinetic energy is
• K.E = ½ x m x V2
11/23/2023
11
Energy transformation
• IT refers to the change of energy from one
form to another. For example, when wood
burns ,its chemical energy changes into
heat energy.
11/23/2023
12
Examples of energy transformation
• The Sun transforms nuclear energy
into heat and light energy.
• Our bodies convert chemical energy
in our food into mechanical energy
for us to move.
• An electric fan transforms electrical
energy into kinetic energy.
11/23/2023
13
Ways of conserving energy
• Putting off fire lamps when they are not in use
• Switching off electrical appliances when they are
not in use
• Not leaving fridges and deep freezers open for a
long time.
• Not putting hot foods in fridges and deep freezers.
11/23/2023
14
Effects of increase in human population on the
demand for energy
• Increase in human population places a higher demand on energy consumption. That
is ,as we increase in population, we use more energy. Growing populations consume
more energy. Availability of energy allows populations to grow . Energy
consumption exerts demands on energy resources, making them scarcer. The most
conveniently used source of energy is fossil fuel (petrol, diesel ,kerosene, l.P.G ).
Fossil fuels are limited in supply because they are not easy to come by and it takes
millions of years to form fossil fuels naturally. IF we do not shift to renewable
sources of energy chances are that our energy supply will be exhausted. Also if that
happens we will have to pay more for energy supply.
11/23/2023
15
Effects of using old electrical gadgets
•
•
•
•
1. You end up paying more for electricity.
2.Some old electrical gadgets may become faulty.
3.Some may also electrocute the user.
4. Old electrical gadgets do not preform well as before.
11/23/2023
16
Summary
• 1. Energy comes in different forms
• 2.Energy can be transformed from one form to another
• 3. The law of conservation of energy states that energy can neither be
created nor destroyed but can be transformed from one form to another
• 4. There should be judicious and wise use of energy
11/23/2023
17
ESSAY TYPED QUESTIONS
• A piece of stone was dropped from a height to the ground .state the energy processed by the
stone,
I.
Just before it was released from the maximum point.
II. Midway between the fall
III. Just before it hits the ground
2.state the energy changes that take place in each of the following processes
a) An orange falls from a tree to the ground.
b) A carpenter hits a nail with a raised hammer.
c) A torch switched on.
d) Dissolving calcium carbide in water.
11/23/2023
18
Essay typed questions
An object of mass 80 kg moves with a velocity of 4m/s calculate the kinetic
energy of the object.
4. Give three ways of conserving energy
b.why has the issue of energy conservation assumed greater importance in
Ghana
11/23/2023
19
Answer to Essay-type Questions
•
•
•
•
•
•
•
1.Potential energy
B. both potential and kinetic
C. Kinetic energy
2. potential energy- potential and kinetic- kinetic energy- sound +heat energy
b. potential energy- kinetic energy- sound + heat energy
c. electrical energy- light energy- heat energy
d. chemical energy- heat energy
11/23/2023
20
Answer to Essay-type Questions
•
•
•
•
•
•
3. K.E of the body= ½ x m x V2
M =80 kg
V=4m/s
K.E 1/2 x 40 x 42
40 x 16 = 640 J
11/23/2023
21
Answer to Essay-type Questions
•
•
•
•
4a
1. putting off fir lamps when they are not in use
2. Switching off electrical appliances when they are not in use
3. close all windows and doors when using an air conditioner
• B.it has because some Ghanaians
• 1. use old gadgets
• 2.do not know about energy conservation
11/23/2023
22
Thank you
11/23/2023
23