Posted by cz on .
A black thinwalled cylindrical can, 10.0 cm in diameter and 20.0 cm tall is filled with water at 100°C and suspended in a 20°C room. Determine the initial rate of heat transfer due to radiation, and the initial rate of change of temperature of the water. (Neglect any calorimetric effects of the can)

u of s 
drwls,
Note that they only ask for the heat transfer due to radiation. Use the StefanBoltzmann law.
The can's temperatuire will be 373 K, initially.
The room temperature is 293 K.
Q = M*C*dT/dt
You want the cooldown rate dT/dt
Q = A*sigma*(373^4  293^4)
C = 4184 J/kg*K is the specific heat of water
A is the can's outside arwea in m^2
sigma is the StefanBoltzmann constant. Assume can and room wall emissivity = 1.
M is the water mass 
u of s 
Anonymous,
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