“The ratio of output to the input is called Efficiency.”
\(Efficiency=\frac{Energy\ as\ output(E1)}{Energy\ as\ input(E2)}\)
𝜂 =E2E1 x 100
Efficiency=(Output/Input) X 100
The rate of doing work is called Power”
Or
“The amount of energy transferred per unit time is called Power.”
When you run up and cover distance in 5 seconds or take a slow walk up the same distance in 20 seconds. You are doing the same amount of work; however, you are doing it at a different rate. When you run up, you are working much faster and you have a higher power than when you walk up. This quantity tells us the rate of doing work
Power=Work done /time taken
P=W/t
The SI unit of power is joules/second = watt
Since work and time are scalar quantities. Therefore, power is also a scalar quantity.
Kilowatt (kW), 1kW = 1000 watts
1 MW =1000000 Watt
1 hp = 746 watts