An immersion heater rated 1200 W is used to heat 2 kg of water from 25∘C to 75∘C in a bucket.
a. (i) Calculate the thermal energy required to raise the temperature of the water to 75∘C. Take the specific heat capacity of water as 4.2×103J kg−1∘C−1.
b. (ii) Assuming the heater is 80\% efficient, determine the time required for the heating process.
c. (iii) If the heater is used once every day, find the total electrical energy consumed in a 30-day month, expressing your answer in kilowatt-hours.