Question

Calculate the rate of heat transfer by radiation from a car radiator at 111 °C into a 45 °C environment, if the radiator has an emissivity of 0.75 and a 1.6 m^2 surface area.

Answer 1

783.63 Watt

Step-by-step explanation:

T = 111 degree C = 111 + 273 = 384 K

T0 = 45 degree C = 45 + 273 = 318 K

A = 1.6 m^2

e = 0.75

According to the Stefan's law, the energy radiated per second is given by

`E = \sigma eA\left ( T^(4)- T_(0)^(4)\right )`

`E = 5.67* 10^(-8)* 0.75* 1.6 ( 384^(4)- 318^(4)\right ))`

E = 783.63 Watt