Work Energy and Power

OP15 define and give the units for work, energy and power, state the relationship between work and power, and perform simple calculations based on this relationship

Follow this link

OP16 classify sources of energy as renewable or non-renewable

Renewable Energy

OP17 state the principle of conservation of energy

Energy can neither be created nor destroyed,

it can be changed from one form to another

This means that the total energy in the universe has never changed but that all that energy is stored in the bodies of the universe. The total energy will never decrease but the way the energy is held will as it moves from one form to the other.

We often say cut down on energy usage, what we really mean is to stop converting useful energy into other energy so we have a supply of this convienient energy in the future. But

We usually use equipment to change energy from one form to other forms,

lets take some appliances what energy do the take in what type of energies come out?

What Energy conversions take place when using


A Television

type of energy in converted to types of energy

Electrical Light energy + Sound energy + heat energy

Microwave Oven

Somebody playing football

Your Mobile phone

Hair Dryer

A car





OP18 explain why the sun is considered our primary source of energy and how this is important in food production and energy supply

We need Energy to do work!

Where do animals get their energy from ?

Where do plants get their energy from ?

Where do we humans get our energy from?

Do we need more than food for our energy needs?

Plants grow in sunlight. this is called photosynthesis

These plants provides food for many animals,

animals that eat other animals are in turn eating the food made from the sun.

All the energy that animals get is from the Sun.

We humans use different forms of energy to do many things.

We all heat our homes by burning some fuel, or

we drive in cars that are powered by petrol or diesel these are fuels too.

We all use electricity to listen to music, to watch TV, to boil the kettle .... and so much more.

Electricity is a form of energy, it is converted in Power Stations, usually from the chemical energy released by the burning of fossil fuels, oil, gas, turf or coal.

Fossil fuels were made from dead plants and animals that only survived due to photosynthesis

Wind & rain is indirectly caused by the sun. The rain and hence river flows are caused by the sun evaporating water into the atmosphere. Wind is actually cause by air in a high pressure area leaving the area for a place of lower pressure. These areas of high pressure are caused by heat from the sun.

Perhaps the only sources of energy not attributable to the sun would be geothermal (gravitaional energy) , tidal (gravitational energy of the moon) and nuclear energy (energy from within the atom).

OP19 list the advantages and disadvantages of different energy sources, including nuclear sources of energy, as part of the solution to national energy needs

The ESB describe some of the advantages and disadvantages on their web page

As this page can be hard to find, I outline these pros & cons to the burning of fossil fuels here

In 2004, renewable energies contributed to less than 9% of the world consumption of energy

The following link takes you to a college paper abstract, but contained within are the various costs and energy production you can expect to get from different types of power stations.

need for energy conservation

In Ireland, we have access to lots of energy.

We import Oil and Gas, to make electricity, to heat our homes and to move our cars and trucks.

Importing energy means that we are

  1. Allowing money to leave our economy
  2. Reliant on the political situations in other countries
  3. Reducing world reserves of crude oil

What you can do to help reduce CO2 emissions and save you mon€y.-

    • Turn off the heater
    • at night before you go to bed (save 600 kg CO2 per quarter)
    • Use a microwave for most of your cooking needs (save 810 kg CO2 per quarter)
    • Use a clothes line rather than a dryer (save 260 kg CO2 per quarter)
    • Drive smoothly with the flow of traffic (save 140 kg CO2 per quarter)
    • You can ask your electricity supplier to source the energy you use from renewable sources such as wind, solar and hydro-power
    • Choosing a clean energy alternative makes it easy for everyone to reduce their greenhouse gas emissions at home and work.
  • Use low energy bulbs.
  • Insulate your home to save energy.
  • Turn off all unnessary electrical appliances.
  • Get solar panals installed on your roof for heating and electricity.
  • Use 'A' rated appliances.
  • Improve your windows so heat doesn't get out and cold doesn't get in.
  • Use your normal shower instead of you electric shower, if possiably.
    • Don't leave things on stand-by or sleep-mode, turn them off.
    • Turn off everything at night.
    • Turn things off at the plug when not in use.

energy wizard from the ESB

eNErGY Effiencey

Energy awareness game from SEI

OP20 identify different forms of energy and carry out simple experiments to show the following energy conversions:










A list of the various types forms of energy.


This the form of energy that moving bodies have. If something is moving it is said that is has kinetic energy, because it would take work to stop the body moving.


All bodies have heat energy, even what we call thing that we think are cold, are not as cold as they might be. They have less heat energy but they still have some. Heat energy is the energy of all the particles (molecules or atoms) added together.


When you hear noise that is sound energy. Sound is caused by vibrations, vibrations are movements with kinetic and so sound energy is very similiar to kinetic energy, because the body is moving.

Sounds are vibrations


Light Energy is given off by Hot objects, light comes in little waves.

We see because light enters our eyes. Our brains and eyes together build up a map of things around us. If there is no light energy we cannot see, as none can enter our eyes. The Light we see is only a little part of the radiation spectrum given off from objects.

Infrared Vision (how light and heat are similiar energies)

Rattlesnakes and other pit vipers use their eyes to see during the day. But at night they use infrared sensory organs to detect and hunt warm-blooded prey. These infrared "eyes" are cuplike structures that form crude images as infrared radiation hits a heat sensitive retina.


Electrical energy is created between bodies that have different charges between each other, a balloon can cling on to a jumper and defy gravity and the force of its weight, due to electrical charge. Our whole lives are helped by the presence of electrical energy in our homes, workplaces, schools, hospitals, in fact it is very hard to imagine life without electricity!


Nuclear energy is the huge supply of energy that is found in the Nucleus of the Atom, If we break the bonds inside the Nucleus we can release great energy. Usually Nuclear energy is used to make electricity in many countries, the UK, France, Germany. However it has not yet been used in Ireland previously due to safety concerns.

Potential Energy

This is the energy that a body has because of its position. Imagine a rock on the ground, can it move? Imagine a rock teetering on the edge of a cliff, can it move? A stone in a catapult, it has no kinetic energy because it is not moving but the elastic properties of the sling will propel it if it is released. This is what is meant by potential energy.


Chemical energy is the energy within molecules that when reacted with some other material gives out energy. When our cells collect energy from the blood it then reacts with oxygen. When we burn materials in oxygen we also react the materials, we are all aware of the heat and light energy that comes from the fire. Other examples include chemical reactions, the reactions inside batteries.


The energy stored in a spring or elastic is really potential energy. That is energy due to position away from the equilibrium point.


the trebuchet taken from

Energy Conversions demonstrations are here

OP21 give examples of energy conversion from everyday experience.

there are plenty of boxes left, what other things can you think of

New look at old light bulbs

national energy needs

Energy awareness game from SEI