I'm guessing that the idea was that the water splats onto the ground,
and that you're supposed to assume that all the kinetic energy of it
falling gets converted to internal thermal energy. (In a real
situation, some of the energy would leave into the ground or as sound
waves, so this calculation will overestimate the actual heating
somewhat.)
One kilogram starts with 50 meters*1kg*10m/s^2 = 500 Joules of
potential energy. That converts to kinetic energy, then to thermal
energy. With a specific heat of 4.2 J/ °C-gm, the heat capacity is 4200
J/ °C. So it sounds like around 0.24 °C is the answer.
Mike W.
(published on 10/22/2007)
