Heat Transfer Questions & Answers  


The efficiency chart in the tables can be used when the tip is not insulated. When the tip is insulated, you can also use the efficiency chart but you need to set $L_c=L$ instead of $L_c=L+t/2$.




Hm, maybe, maybe. But you should be able to deduce this from the problem statement..




This seems ok, but is beyond the scope of this course thus. But thanks for sharing this with us!






You can set the direction from left to right and if $q$ ends up being negative it means your guess was wrong. What matters is to be consistent. If you draw $q$ from left to right and $q$ is negative in your answer, then keep the answer as negative but make a note that the heat transfer is going from right to left.




I don't understand. If it has steel cables in it, the cylinder must be hollow. It can not be full.




Yes of course.




Radiation heat transfer coming out of objects at 300 K is generally quite small compared to convection heat transfer. It becomes more important thus when the temperatures are higher because its intensity scales with the 4th power of the temperature. At low temperatures, you can ignore it. But at higher temperatures, you should take it into consideration unless there's not enough information to calculate it.




Sure, you must use an iterative method for this problem.




You should use shape factors here. Think about it more.




There's a reason why this is not given. Think about the problem more.




Explain to us how you can calculate the sun's temperature.




How can you find the temperature of the sun? I can't follow you. I see no equation $T_{\rm sun}=..$.



$\pi$ 