PEAZIT Aha card
Go straight to resources ↓Power: doing the same work faster
Power measures energy transfer per time. One joule per second is one watt. Doing the same work in half the time requires twice the average power.
| Observation | What it means |
|---|---|
| 600 J in 3 s | 200 W |
| 600 J in 6 s | 100 W |
One worked example
- W = 900 J, t = 3 sDistinguish the symbol for work W from the unit watt W.
- P = 900/3Divide work by time.
- P = 300 WThe average transfer is 300 J each second.
Watch out: Power is not efficiency. Efficiency compares useful output energy with input energy.
Goal, prerequisites and card origin
What you will learn: Calculate average power P = W/t.
What you need first: Work, energy and time.
An original PEAZIT working card. Independent expert review and effectiveness testing have not yet taken place. · v1
Reference for the underlying principle ↗Show connections
Power measures energy transfer per time. One joule per second is one watt. Doing the same work in half the time requires twice the average power.