Question

A 9-cm-diameter spherical ball whose surface is main­tained at a temperature of 110°C is suspended in the middle of a room at 20°C. If the convection heat transfer coefficient is 15 W/m2·°C and the emissivity of the surface is 0.8, determine the total rate of heat transfer from the ball.

Answer 1

Answer:

the total rate of heat transfer from the ball = 50.59W

Explanation:

The application of heat transfer by convection and radiation was used to solve the question. For heat transfer by radiation involves the emissivity and the stefan boltzmaan constant, for heat transfer by convection involves the area and the heat transfer coefficient. The addition of both heat transfer in both medium is used to calculate the total heat transfer from the ball.

The steps is as shown in the attachment.