Power Delivered

Power P is the rate of doing work or transferring energy: P = dW/dt.

Units: watt (W) = J/s. 1 kW = 1000 J/s.

Average power: P_avg = W/Δt. Instantaneous: P = F·v (for constant or varying force).

Power required to move at constant velocity against friction: P = F_friction × v.

Acceleration phase: P keeps increasing if you maintain F = F_friction + ma.

Power output of a car engine: V_max occurs when all engine power goes against drag — P = F_drag × V_max.

Vehicles, machines, appliances all rated by power. Human body produces ~75 W steady; up to ~1500 W in short bursts.

Electrical: P = VI = I²R = V²/R. Mechanical: P = F·v.