The document discusses energy transformations and efficiency. It provides examples of energy block diagrams and Sankey diagrams to illustrate how energy from one form is transformed and used, as well as wasted, in various everyday situations like using a hair dryer or moving a lorry. Activities are described to have trainees draw diagrams to analyze energy transformations when using a computer.

1. 10 October 2010 2.2 Describing energy Jenny is a trainee engineer working for an aerospace company. She is working with other engineers to design a more efficient engine for aeroplanes. They want the engine to transform as much energy as possible into useful forms and to reduce the amount of energy that is wasted. Which types of energy given out by the engine are wasted?

2. Investigating energy You need to describe energy changes that take place in everyday situations

3. What energy does the ball have? Ball on a bench Falling ball Ball rebounding

4. We use energy block diagrams to understand how energy is transformed Electrical energy used for radio, lights, recharging battery etc Tracking transformations Chemical energy from burning fuel Kinetic energy used to move the lorry Wasted thermal and sound energy

5. Activity A: Draw a block diagram to show the energy transformations for someone using a hair drier

6. Activity A: Draw a block diagram to show the energy transformations for someone using a hair drier Heat from heater Electrical energy from mains Kinetic energy from fan Sound of fan

7. Useful versus wasteful It is sometimes good to know exactly how much energy is being used We use a sankey diagram to show this The width of the arrows shows the amount of energy

8. Electrical energy used for radio, lights, Recharging battery etc. 20 000J Wasted thermal and sound energy 100 000 J Chemical energy from Burning fuel 200 000 J Kinetic energy to move the lorry 80 000 J

9. Assessment activity 2.2 You are working for a leading IT company. Your manager wants you to look into energy efficient computers. To start you investigate the energy used by one of the company’s existing computers. 1. State in words the types of energy involved when the computer is in use P1 2. Draw a block diagram to show the energy transformations M1 3. 350 J of electrical energy is supplied to the computer. In the process 65 J is used to generate light energy, 190 J is transformed into heat and 95 J into sound. Draw a Sankey diagram to show the energy transfers.