2. Describe energy as the capability to move
an object.
Energy is the ability of a body to do work.
And work is done when force causes an object to move.
When one object does work on the another, energy is transferred from the first object to the
second object. This energy allows the second object to do work.
Moving objects have energy. For example: a moving ball can do work by knocking something
over.
3. Energy resources
We need energy in our day to day life to do various work.
Where does all of this energy come from?
We have various natural sources from where we get energy for our daily use.
An energy resource is something that can produce heat, power life, move objects, or produce
electricity.
4. Classification of energy resources
Non- renewable energy: Non-renewable energy are those which once gets finished cannot
be replaced for millions of years.
It is a resource that forms at a rate that is much slower than the rate at which it is consumed.
Some of the examples of non- renewable energy resources are: fossil fuels (like coal, oil, gas) and nuclear
energy.
5. Explain fossil fuels
Fossil fuels are energy resources that formed from the buried remains of plants and animals that lived
millions of years ago.
Plants store energy coming from the sun by photosynthesis, and the animals eat these plants and store
these energy in them.
So fossil fuels are basically the concentrated form of sun’s energy.
Burning coal is a very common way to generate electricity.
6. Advantages and disadvantages of fossil
fuels
Advantages :
It provides a large amount of thermal energy.
Easy to get and transport
Disadvantages :
Non-renewable
Produce smog
Release substances causing global warming and acid rain.
7. Nuclear Energy
Another way to generate electrical energy is to use nuclear energy.
Nuclear energy is generated from radioactive elements.
Advantages: does not produce air pollution
Disadvantages: produce radioactive waste and is non- renewable.
8. Renewable resources
Solar Energy: sunlight can be changed to electrical energy through solar cells. Can
be used in calculators, solar panels etc.
Advantages: it is limitless and do not produce pollution
Disadvantages : expensive for large scale production and practical only in sunny
areas.
Water/ hydro energy: Water energy is energy derived from the power of water,
most often its motion. Water falling from dam turns turbines to generate
electricity.
Advantages: renewable and do not produce air pollution.
Disadvantages : requires dam, disrupting the ecosystem of river.
9. Wind energy: Wind energy (or wind power) describes the process by which wind is used to generate
electricity. Wind turbines change the kinetic energy to electrical energy by turning a generator.
Advantages: relatively inexpensive to generate and no air- pollution.
Disadvantages : is practical only in windy areas.
Geothermal energy: Thermal energy caused by the heating of earth’s crust is called geothermal energy
Advantages: limitless source and power plants require less land
Disadvantage: practical only in areas near hot spots, produces waste water.
Biomass energy: plants use and store energy from the sun. organic matter, such as plants, wood, and
waste that can be burned to release energy is called biomass.
Advantages: renewable and inexpensive
Disadvantages: large areas of farmland required and produce smoke.
10. Explain the various forms of energy
There are various forms of energy that we encounter in our day to day life.
The first among them is kinetic energy.
Kinetic energy of an object is the energy that it possesses due to its motion.
For example: A skier traveling down a hill has a large amount of kinetic energy
11. • The second form of energy is potential energy.
• Potential energy is the energy in a body due to its position.
• Any object which is kept at a height relative to the ground is said to
have a potential energy
• Mechanical energy= kinetic energy + potential energy
• Mechanical energy is the sum of kinetic and potential energy in an object that is used to do work.
12. Thermal energy
• Thermal energy is all of kinetic energy due to the random motion of the particles that make up an object.
• All matter is made up of particles that are always in random motion.
• Particles move faster at higher temperatures than at lower temperatures.
• The faster the particle moves, the greater is its kinetic energy and greater the thermal energy.
13. Chemical energy
• Chemical energy is the energy of a compound that changes as its atoms are rearranged.
• It is a form of potential energy because it depends on the position and arrangement of atoms in a
compound.
14. Electrical energy
• It is the energy possessed by moving electrons (electrons are the negatively charged particles in an atom.
• The electrical outlets in our homes allow us to use electrical energy.
• The various electrical appliances in our homes use electrical energy.
15. Sound energy
• Sound energy is caused by an object’s vibrations.
• Vibrating object transmits energy through the air around it.
• It is a form of kinetic energy.
Light energy
• Light energy is produced by the vibrations of electrically charged particles.
• Like sound, light vibrations can cause energy to be transmitted, but light energy doesn't require any medium
to travel.
16. Energy transformations
• Energy can be converted from one form to another form.
• Energy conversions are needed for everything we do.
• Heating our homes, getting energy from meal and many other things use
energy conversions.
• For example a hair dryer changes the electrical energy into thermal energy
which helps you to dry your hair.
17. Principal of conservation of energy
The law states that energy can neither be created and nor be destroyed, it can
only be transferred from one form to another.
18. BEE star rated appliances
BEE stands for Bureau of Energy Efficiency.
The star rating is a measure of energy efficiency of an appliance.
It is a five points scale where higher the rating lower is the energy consumption
and hence better savings.
Usually, you can find a BEE Star Label on heavy electrical home appliances like
Air conditioners, Refrigerators and Washing machines etc. with a number of
stars it has got and an estimated power consumption of the appliance in a
year that it is expected to consume.
