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Paying for Electrical Energy

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Know that energy can be measured in units of kWh

Be able to use an alternative set of units in order to calculate energy



Task 1 - Recap

Remind the person next to you:

- the units normally used to measure energy.

- the units gas and electricity companies use to measure energy.

- the definition of a Watt.

- the definition of a kilowatt-hour.



Task 2

Somewhere in your home is an "electricity meter", like the one in the picture below.  Each time a kilowatt-hour of electrical energy is used, the number increases by 1.  The electricity company looks at how much the reading has increased each month and charges you a set rate for each "unit" (kWh) of electrical energy you have used.


A unit of electricity costs around 14p.  The total cost of the electricity used can be calculated using the formula you learned last lesson:


Cost = units used cost per unit





Task 3

Complete the problems on this worksheet, by working out the number of units used and the cost of electricity.  Your teacher will help you to complete the first one as an example.




Task 4