Work and Energy


Rate of doing work

Tanusri Gururaj, Academic content writer of Physics at Edumarz

  • Power is the rate of doing work. It measures the speed at which the work is done. 

Power = Work//Time

Unit: Watt (W)

  • 1 watt can be defined as the power of an agent when 1 joule of work is done per second.

  • Average power = total energy/total time taken

  • 1 kilowatt hour (kWh)

It is the energy used in an hour at a rate of 1000 joules per second.

1 kWh = 1 kW x 1h

= 1000W x 60s x 60s

= 3.6 x 106 J

Energy used in industries, households, etc is expressed in kilowatt hour as the unit joule is too small to express large quantities of energy.

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