Energy & Power
Science: KS3, topic 3.1.11
Power
Power is the rate of energy transfer (or work done). The faster that energy is transferred (or work is done), the higher the power.
Speakers
- The more powerful a set of speakers is, the more sound energy will be produced.
Lightbulbs
- The more powerful a lightbulb is, the more light energy will be produced.
Equation for power
- Power is the rate of energy transfer.
- We call energy transfer 'work done'.
Power equation
- Power is equal to the work done divided by time taken.
- Power is measured in watts, work done in joules, and time in seconds.
Test yourself on Energy & Power
What is power the rate of?
Loudspeaker A produces less sound energy each second than Loudspeaker B. Which loudspeaker has the higher power?