Recent content by redbaldyhead

Homework Statement B=10^-7Wm^-2Hz^-1sr^-1;T=10^4K h=6.6x10^-34J.s k=1.4x10-23JK^-1 c=3.0x10^8m^-1 Homework Equations Calculate v fom Bv(T)=(2hv^3)/(c^2)x1/(exp(hv/kT)-1) The Attempt at a Solution I have managed to obtain a LHS= (Bc^2/2h)xexp(h/kT) but RHS is posing a problem...

Actually =Bc^2 exp(h.kT)/2h I think I correctly calculated the exp(h/kT) bit but I just can't figure out the rest of the equation on the RHS Thanks for looking

Sorry for the delay in responding! No it is the RHS of Planck's equation for B(v)T The LHS as I have reduced it to =Bc^2/2H

I can't resolve v(cubed)/exp(v)-1 which is the RHS of an equation that has been sorted out of the left! I am rather hoping that this becomes v(cubed)/v which simplifies to v^2. Thanks

Can anyone help me get my head around this one? A star with a parallax angle of pi = 10 millisecs and has apparent magnitude of V= 10.2 How can I determine absolute magnitude: I have the formula M=v -5logd -5 +A which can be ignored. d=1/pi but I am always determining d which is less than...

Thanks to all you good guys! Is the Planck function mentioned above, valid for high frequency range where v>>kt/h? What would a graph look like; v against kt/h?...an exponential rising upwards and rapidly from 0. How would the range on the y-axis appear 10^-1 to 10^-10 for example or the...

Thanks 82 I actually thought that the result would be of little consequence; I'll look closely at the differentiation! Obviously now that I see it, with h=constant and K=constant, any overall increase over 1 must mean the value of v increases against T which I assume doesn't change either...

Thanks for looking; I have been looking at Rayleigh Jeans Formula and I need to understand what happens for hv>>kT

for hv>>kT how does exp(hv/kT) compare to 1? I understand hv >>KT leads to an exponential fall in brightness but why did Planck introduce 1 in his equation. and only for values hv<<kT can this exponential be expanded! Thanks for any help!