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#4 A copper ball with a diameter of 10 cm is at 70 °C throughout and then is suddenly inserted into flowing air at 20 °C. The surface temperature of the ball is measured by a thermocouple to be 55 ° C one minute after the ball is inserted into the flowing air. Assuming that the temperature of the ball is uniform throughout as it cools, determine the heat transfer coefficient (h, W/mK) for this the flow over the ball. Then, verify our assumption that the temperature throughout is uniform. Copper: k- 401 W/m K, 117 x10-m2/s, p 8933 kg/m. Cp 385 J/kg K
engineering   Mechanical-Engineering   
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