Question

4. You will experience a significant convection cooling effect when you extend your arm outside the window in a moving vehicle or into a flowing water stream. Assume that the surface of your hands is at a temperature of 32 'C. You dip one of your hands in a stream of cold water at 10 C, and another in a stream of cold air. The convective coefficient for the water stream is 45 Wm2K I, while for the air stream it is 12 Wm2K-1. You notice that you lose heat ten times as fast from the stream of water than the stream of air (i.e. qwater 1. If you can neglect all modes of heat transfer except convection from the surfaces of your hands, estimate the temperature of the air stream. water hands is at a temperature of 3

Answer 1

Stepl: Te= 32°C. rn ts Too Step2. to : 990 to sale Too 32-a9 12 99 12 (32-TO 32-4) Tempesahur 12.