AskIITians Expert Hari Shankar IITD
Last Activity: 15 Years ago
By the stefan boltzmann law,
Rate of heat loss from the ball will be
E = seA(T4 -Ts4)
where s =Stefan-Boltzmann constant = 5.67 e-8 units (SI units, I dont remember the units exactly, but you should always right the correct units)
e = emissivity = 0.4
A = 200 cm2 = 200 * 10-6 m2 = 2e-4 m2
T = Temp. of ball = 527 C = 527+273 K = 800 K
Ts = Temp of surroundings = 27 C = 300 K
Putting in all the values,
E = (5.67e-8)(0.4)(2e-4)(8004-3004) = 1.85 J/s