One kilowatt hour (kwh) is the amount of work or energy generated when one kilowatt of power is supplied for a time of one hour. a kilowatt hour is the unit of energy used by power companies when figuring your electric bill. determine the number of joules of energy in one kilowatt hour.

The definition of Power tells us that it is the amount of Energy supplied during a certain period of time.

In this case 1 kWh is the amount of energy released during a period of 60 minutes to replace a given task.

In practical terms 1kW hour is the equivalent of one thousand Watts, that is

Where

P = Power

E = Energy

t = time

The power is equal to 1000W or 1000J/s through a hour, then

Therefore the number of Joules of energy in one Kilowatt hour are

the answer is b, have negligible mass