Help! E=mc^2 and heat

1. Mar 15, 2005

pinkie

I posted this on the college board, but think it should go here. It is a college course, but at a high school level.
I feel kind of silly because this is probably a very basic problem, but I'm having problems with physics in general. Would anyone be able to tell me if I'm on the right track for the following question (we are focusing on Einstein's theories of relativity right now)?

1. Is the mass of a frying pan different when it is hot compared to when it is cold?

Yes it is, as E=mc^2 proves. Because the mass is equivalent to the energy of the object, when the energy increases, so does the mass. As energy increases when an object is heated, the mass of the pan will also increase when it is heated. The mass will decrease when the pan is cool and the energy has decreased.

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I hope I have this right. Lately I feel very hopeless at physics. Any help or comment would be very much appreciated

2. Mar 15, 2005

Andrew Mason

Yes. You seem to grasp the essential point about mass-energy equivalence (as long as you understand that the change in mass is so small as to be unmeasureable).

Physics seems hard, in part, because it builds on concepts and principles. If you are having trouble, go back and redo something you think you really understand and work back up to the thing you are trying to understand. You will invariably find that there was something earlier that you thought you understood but didn't quite. Also work on problems, problems and more problems.

And then again physics seems hard because it is. But that just makes it all the more rewarding when you discover that you understand something new. Like E=mc^2.

AM

3. Mar 15, 2005

pinkie

Thank you. I really appreciate the help. Physics is very new to me, so I guess you are right to tell me to practice. Thanks again. :)