Simulation · Physics · Class 11
Power and speed: P = Fv
From the lesson Power in Work, Energy and Power. Change the values and watch what happens.
Power and speed: P = FvPhysics · Class 11
The idea behind it
NCERT § "Power"
- Power is the rate of doing work. Average power = W/t; instantaneous power P = dW/dt.
- Instantaneous power can also be written P = F·v, the dot product of force and velocity.
- The SI unit of power is the watt, 1 W = 1 J s⁻¹. One horsepower is 746 W.
- The kilowatt hour is a unit of energy, not power: 1 kWh = 3.6 × 10⁶ J.
- A pump lifting mass m of water through height h in time t does useful work at the rate mgh/t; if its efficiency is η, the input power is (mgh/t)/η.
- Efficiency is useful output power divided by input power and is always less than 1 for real machines.