Answer
255 kg of water can be heated per hour.
Work Step by Step
The water heater can generate 32,000 kJ of energy each hour. We can find the mass of water which can be heated by $30^{\circ}C$ each hour. Therefore;
$Q = mc~\Delta T$
$m = \frac{Q}{c~\Delta T}$
$m = \frac{3.2\times 10^7~J}{(4186~J/kg~C^{\circ})(30^{\circ}C)}$
$m = 255~kg$
255 kg of water can be heated per hour.
