A 3kW electric water heater is used to warm water in a storage tank. To reach the desired temperature, the water must absorb 5400kJ of energy.
(i) Convert 5400kJ of energy to joules.
(ii) Calculate how long, in seconds, the heater must run to supply this energy at its rated power.
(iii) Express the time obtained in part (ii) in minutes (rounded to one decimal place).