The water that cools a reactor core enters the reactor at 216 °C and leaves at 287 °C. (The water is pressurized, so it does not turn to steam.) The core is generating 5.6 × 109 W of power. Assume that the specific heat capacity of water is 4420 J/(kg ? C°) over the temperature range stated above, and find the mass of water that passes through the core each second.