Interactive Resources for Schools
This topic takes on average 90 minutes to read.
There are a number of interactive features in this resource:
Biology
Chemistry
Physics
PSHE / Citizenship studies
Science
Biology
Chemistry
Human biology
Physics
PSHE / Citizenship studies
Science
Physics
Science
Physics
Science
The power (W) can come from the power rating of the item, and this means the amount of energy transferred every second. Therefore, the energy transfer can be calculated for appliances in the home.
Both joules and watts can also be in kilojoules (kJ) or kilowatts (kW) if the number is large. To do this, divide the joules or watts by 1000.
Example:
1. A 850 W washing machine takes 1 hour to wash one load. What will be the energy transfer in kilojoules?
- First, convert 1 hour to seconds: There are 60 minutes in an hour and 60 seconds in a minute.
60x60=3600 seconds in an hour.
- Then, time in seconds (s) can be multiplied with the power rating to work out the energy transferred.
850 W x 3600 s = 3,060,000 J
- The energy transfer is 3,060,000 J. This can be converted to kilojoules (kJ) by dividing by 1000.
3,060,000 J / 1000 = 3,060 kJ
Complete the 10 energy transfer problems below.
