Power
The rate at which work is done or energy is transferred, calculated as P = W/t or P = E/t, measured in watts (W), where 1 W = 1 J/s. Instantaneous power is P = F·v (force times velocity). Power quantifies the speed of energy transformation.
Formula
P = W/t | P = Fv
Real World
A 100W LED floodlight at Wembley Stadium converts 100 joules of electrical energy into light (and heat) every second — compare to a 1W phone charger: same energy type, vastly different rate of transfer.
Exam Focus
Use P = Fv for moving objects (engines, cyclists); use P = W/t when time and total work are given — choose the form that matches available data.
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