Comparing Cube A & B's Temperature Change

[pogochewy]

Homework Statement

If the same quantity of heat were delivered to two cubes A and B, and the only difference between them is their thermal conductivity K, would they both have the same final temperature? Assume convection as the main heat loss component from each cube.

Relevant Equations

Heat transfer equation

I know in this case cube A would heat up faster, but would cube B eventually reach the same temperature?

 

[berkeman]

Welcome to PF.

What do you think, and why? Also, how are you heating these cubes? From one face only? Somehow on all faces equally? The two cubes are not in contact, right?

 

[pogochewy]

Welcome to PF.

What do you think, and why? Also, how are you heating these cubes? From one face only? Somehow on all faces equally? The two cubes are not in contact, right?

It's a constant heat flux applied to only the bottom surface of each cube, and the cubes are not in contact. I'd think they would end up at the same temperature over a long enough time period. The cube with the higher k would get there faster. But I was second guessing thinking that the cube with the lower k would not absorb as much heat and would not ever get to the same temp as cube A.

 

[Orodruin]

Please define your quantities. Do not assume the same notation is used everywhere.

 

[pogochewy]

Please define your quantities. Do not assume the same notation is used everywhere.

I added further definition. There are no numbers in this question, it is theoretical where everything is equal except the thermal conductivity of the cubes. I am curious if the cubes will end up at the same temperature (so temp as t goes to infinity is independent of K) or not.

 

[gmax137]

Why was this thread deleted? I was working up a reply but when I came back here to post it, the question has been "deleted"

Annoying. I'm just glad I didn't spend waste too much time on this

 

[berkeman]

Why was this thread deleted? I was working up a reply but when I came back here to post it, the question has been "deleted"

Annoying. I'm just glad I didn't spend waste too much time on this

This happens every so often here at PF. A student comes here as a newbie poster, posts a homework question (sometimes in the technical forums), and after getting some useful replies they delete their OP and their replies in the thread in hopes that other students in their class and the instructor don't find the thread because they are not supposed to be getting online help.

The Mentors have the ability to restore such deleted posts, as I have done in this case. That makes it so that the instructor can indeed find these types of attempts at cheating.

Accordingly, after having been restored, this thread is closed. The OP has earned a 10-day ban from PF. If they return after the ban, they will be on a short leash.

Have a nice day.