Level 4 Engineering Science Energy

Energy Unit When you have completed this unit you should be able to: Correctly identify various forms of energy Correctly identify various forms of energy at various stages within a system. Correctly describe how energy changes take place within a system. Clearly explain where energy losses take place within a system.

What is ENERGY? -Energy is all around us and comes in many different forms. -It cannot be seen or touched - Energy is often defined as the ability to make things happen e.g. we can give a golf ball the energy to move by hitting it with a club as shown below.

Where does it come from? -The Sun -The Food we eat -The petrol in our cars -Hydrogen in rocket fuel

How we use ENERGY energy cannot be created or destroyed

Different types of ENERGY Kinetic Potential Electrical Strain Thermal

KINETIC ENERGY Kinetic energy is the energy of movement.

POTENTIAL ENERGY Potential energy can be best thought of as energy stored in a static object.

POTENTIAL & KINETIC ENERGY Potential and Kinetic Energy have a relationship, both objects, the car and the bucket when still have potential energy when the start to move it becomes kinetic energy. The Video clips below demonstrates the relationship between the two. DIVER ROLLER COASTER

ELECTRICAL ENERGY Electrical energy is one of the most convenient and commonly used forms of energy It can be transported easily from place to place ( along electrical cables ) and can be easily changed into other forms of energy. Most electrical energy is generated in power stations where one type of energy is converted into electrical energy. ELECTRICAL ENERGY GENERATION

STRAIN ENERGY Strain energy is the energy stored when a body is stretched or compressed. The diagram left shows an elastic band, which has been stretched and therefore contains strain energy.

HEAT ENERGY Thermal energy is the energy transferred to a body, which results in a change in the body’s temperature.

ENERGY CONSERVATION In everyday usage the term energy conservation has come to mean conserving energy in the sense that less of it is used to do the same amount of work.

ENERGY CONVERSION A light bulb converts electrical energy into light energy.

ENERGY CONVERSION GEOTHERMAL POWER STATION The heat energy in the rocks is transferred to the water in the injection hole pipe. This hot water is changed to high-pressure steam and transported to the surface. The heat energy from the steam is used to turn the blades of a turbine producing rotational kinetic energy, which is used to create electricity from a generator.

ENERGY CONVERSION HYDRO ELECTRIC POWER STATION Hydro electric – how it works A look at electricity generation in the United States

ENERGY CONVERSION Energy “losses” during conversions Although we have stated that energy cannot be destroyed and that the energy output from a system is equal to the energy input to the system, not all the energy in the system is used efficiently. An electric motor converts electrical energy to produce kinetic energy along with sound energy and heat energy.