A household kettle with a rating of 12kW is heated with 250V

A household kettle with a rating of 1.2kW is heated with 250V supply in the morning in order to make coffee. On the average, 1.2 litre of water is heated from 20 degree C to 95 degreeC in 3minutes. Assume 1 litre has 1kg mass and the price of electricity as at the time from ESKOM is r1.85 per kWh. (Specific heat capacity is C=4187J/kgK). Determine The total heat energy absorbed in the water with each heating.

Solution

heat =mc*(t1-t2)

=1*4.187*75=314.025 J