Question

A 200 W vacuum cleaner is powered by an electric motor whose efficiency is 70%. (Note that the electric motor delivers 200 W of net mechanical power to the fan of the cleaner). Calculate the rate at which this vacuum cleaner supply energy to the room when running. ?

Answer 1

The rate at which this vacuum cleaner supply energy to the room when running is 285.71 Watts.

Step-by-step explanation:

power efficiency of electric motor = 70% = 0.70

The power output of the vacuum cleaner =
`P_o`= 200 W

The power output of the vacuum cleaner =
`P_i`

`Efficiency=(P_o)/(P_i)`

`0.70=(200 W)/(P_i)`

`P_i=(200 W)/(0.70)=285.71 W`

The rate at which this vacuum cleaner supply energy to the room when running is 285.71 Watts.