Recent content by yellowputty

Hello Physics Forums, In my project work, I've had to use the LMA technique for some non linear fitting. I really want to understand what it's doing rather than just using it. I have a poor knowledge of non linear fitting so please bear with me! When producing the line of best fit, it...

I think I just worked it out. Colour has nothing to do with a materials ability to absorb and hence emit thermal radiation. Colour is important in reflecting and absorbing wavelengths in the visible spectrum only. A white material will reflect all visible wavelengths, but a black surface would...

Homework Statement Hello, I'm a little confused. I did an experiment today with a Leslie Cube. One of the faces was a black paint, and another a white paint. I know that white reflects well and has a low emissivity, at least in the visual wavelengths. In the Leslie's cube, was hot water, so...

Hello, Can someone please briefly explain to me why, if I have a system (water) T1, and introduce it to a heat bath of temperature T2 (where T2>T1), and the are left to reach equilibrium, that the total entropy change does not depend on the mass of water? Thank you.

Do I find (\Delta t) by doing SQRT[(4^2)-(3^2)] = ROOT 7 Then at they are both at the same coordinates in the inertial reference frame, we can ignore x , y and z. Therefor S equals the root of (c^2)*(ROOT 7) = 7.9x10^8m Is this correct?

Homework Statement Two events occur at the same place in an inertial reference fram S, but are separated in time by 3 seconds. In a different frame S', they are separated in time by 4 seconds. (a) What is the distance between the two events as measured in S'? (b) What is the speed of S...

Thank you :)

Could someone please explain to me why stationary neutrons may radioactively decay but protons may not? Thank you in advance :)