An automobile radiator may be viewed as a cross-flow heat exchanger with both fluids unmixed. water, which has a flow rate of 0.05 kg/s, enters the radiator at 400 k and is to leave at 330 k. the water is cooled by air that enters at 0.75 kg/s and 300 k. (a) if the overall heat transfer coefficient is 200 w/ m2 k, what is the require heat?