You've experienced convection cooling if you've ever extended your hand out the window of a moving vehi- cle or into a flowing water stream. With the surface of your hand at a temperature of 30°C, determine the convection heat flux for (a) a vehicle speed of 35 km/h in air at -5°C with a convection coefficient of 40 W/m2 · K and (b) a velocity of 0.2 m/s in a water stream at 10°C with a convection coefficient of 900 W/m2 · K. Which condition would feel colder? Contrast these results with a heat loss of approximately 30 W/m2 under normal room conditions.