Water flows steadily through a 30-ft-long pipe from a hot water heater to a faucet. The velocity is 9 ft/s. At the water heater, the temperature is constant at 180oF. Due to heat losses along the pipe, the water temperature at the faucet is constant at 165oF. Assume the temperature gradient along the length of the pipe is uniform. Determine the time rate of change of water temperature as it flows through the pipe using the material derivative of temperature.