Comparing Q=mc(T-t) and E=sigmaT^4 for Calculating Temperature Change in a Body

AI Thread Summary
The discussion compares two formulas for calculating temperature change: Q=mc(T-t) and E=sigmaT^4. The first formula calculates the total thermal energy in an object, where c is specific heat, m is mass, and T is temperature. The second formula, known as the Stefan-Boltzmann law, describes the power radiated by a black body based on its temperature. Both equations are relevant for analyzing temperature changes, as they operate through different mechanisms. The conversation highlights the necessity of using both equations in heat transfer analysis.
Sobi
Messages
19
Reaction score
0
This homework question was originally posted in another forum so there is no template
I know two formulas which is to do with change in temperature,first one is : Q=mc(T-t) and the second one is
E=sigmaT^4. My question is the difference between these two and where we have to use either of these?
 
Physics news on Phys.org
I know a lot more formulas, but if I want to know what they are about, I need to look up the context in the place where I found them ! Did you do that also ? You are apparently reading up on heat transfer ?
 
The first is the total thermal energy which is contained within any object, ##c## is known as the specific heat, ##m## is the mass of the object and ##T## is the temperature. The second is know as Stefan Boltzmann law and describes the power radiated from a black body in terms of its Temperature ##T## with ##\sigma## that is the Stefan Boltzmann constant ...
 
Imagine having a body which has got a higher temperature than it's surrounding.we know that it will lose energy until it reaches the same tempreture as the other bodies around it.which one of those two asked in the first question will do this.
 
Both will do this. They use different mechanisms.
 
Sobi said:
Imagine having a body which has got a higher temperature than it's surrounding.we know that it will lose energy until it reaches the same tempreture as the other bodies around it.which one of those two asked in the first question will do this.
You need to use both equations in your analysis of the problem.

This is obviously homework which is misplaced in the wrong forum. I am moving it to a homework forum and issuing a warning.

Chet
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top