Power

Power

Definition:
Power is the rate of doing work or the rate of energy transfer.

Key idea:
Same work done in less time → greater power

Equation:
$P = \frac{E}{t}$ or $P = \frac{W}{t}$

Where:

• $P$ = power (W)
• $E$ = energy transferred (J) or $W$ = work done (J)
• $t$ = time taken (s)

Exam tips:

• mention time when explaining power
• Use ‘rate of energy transfer’
• Do not confuse power with energy