Formula triangle for P, E, t:
Draw a triangle with P at the top, E on the bottom-left and t on the bottom-right. Cover the letter you want to find:
- Cover P → P = E/t
- Cover E → E = P × t
- Cover t → t = E/P
The tap analogy: Energy is like water in a tank. Power is like how wide you open the tap. A wide-open tap (high power) empties the tank quickly. A trickle (low power) takes ages. The same total volume of water (energy) flows either way — power just determines how fast.
Remembering 1 W = 1 J/s: Think "one Watt delivers one Joule per Second" — W-J-S in alphabetical order (kind of).
This memory aid covers Memory Aids within Power for GCSE Physics. Revise Power in Energy for GCSE Physics with 14 exam-style questions and 25 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 9 of 12 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
Practice questions for Power
Which of the following is the correct definition of power?
A microwave oven transfers 54,000 J of energy. It has a power rating of 900 W. Calculate how long the microwave was switched on. Use the equation: power = energy transferred / time Give your answer in seconds (s).