An electric kettle is required to heat 0.6 litre of water from 10 Celsius to boiling point in 5 min, the supply voltage being 240V. The efficiency of the kettle is 78%. Calculate : a) the resistance of the heating element; b) the cost of energy consumed at 8.0p/kWh. Assume the specific heat capacity of water to be 4190J/kgK and 1 litre of water to have a mass of 1 kg.
I've manage to find the resistance, which is 59.57 ohm, but I don't have any idea on hove to find the second answer (in fact, I didn't saw that unit before! I don't know what that unit means!)
Anyone can help? A hint or a formula would be please...Thanks a lot!!