The equations needed to solve this problem are outlined below. E = mc(T_{2} - T_{1}) d = m/v P = E/tYou first need to work out the mass of the water. m = 1000 x 4.5 = 4500kg You then need to work out the amount of energy produced by the heater in one hour. 2700 = E / (60 x 60)E = 9.72 x 10^{6}JThe change in temperature of the water can then be calculated.9.72 x 10^{6} = 4500 x 4200 x (T_{2} - T_{1})Change in T = __0.51K__