Hi, can anyone explain satellite beam weights, I think more precisely, phase weights and amplitude weights. I am starting a job next week and at my interview they mentioned these. I am trying to read up on these before I start and can't find anything useful on the internet.
Many thanks.
Most people say it is due to friction with the atmosphere, however I have read that this is a misconception and that the majority of the heating effect comes from the rapid compression of the air infront of the meteorite as it travels at very high speeds. Which is the right answer please. (from...
Oh yeah! So if iI have the formula for the area then I need to differentiate twice then set equal to zero to get the maxima? I did this and got V^2=(18 pi k T/m)^1/2. This doesn't match the answer so I don't know if my working is wrong or something else.
Homework Statement
The area under the Maxwell-Boltzmann distribution of speeds of molecules of mass m in a gas at temperature T above a speed v can be estimated as
1/2 (m/2πkT)^(1/2) v exp(-(mv^2)/kT)
Show that the maximum likely speed of a gas molecule in the air in a typical room...
yeah, I got that far then tried equating the forces along a horizontal line level with the pushing piston when the mass had been raised a height h:
P1 = mg/A2 + rho g h2 => F1 = mg + rho g h2 A2 => m = F1/g – rho h2 A2 (1)
Also, conservation of energy:
Work done pushing piston down = Force...
Hi, this really isn't a homework problem - it's posed in a textbook I am using to revise having not used physics for 15 years - I'm now training as a science teacher.
Can anyone prove the hydraulic formula to raise a mass m by distance d where the force on the piston must be increased by...
Homework Statement
(a) A 0.5kg mass of copper (specific heat 385 J kg-1K-1) at 600K is plunged into a litre of water at 20C. What is the equilibrium temperature, T2, of the system? What is the change in entropy of the water?
(b) A litre of water is heated slowly at a constant rate from 20C...
Hi, I used the Rydberg formula 1/λ=E/hc=RZ^2 (1/(n_1^2 )-1/(n_2^2 )) and used the same R for the hydrogen and unknown atom. First I assumed the transitions were the same which leads to E_unknown/E_H =Z^2 and gives Z=22.6, as before using the Bohr formula. Then I tried different n values and...
Ok, that makes sense now, many thanks. However, having tries a few n values for energy level transitions I cannot get anything values for Z that look viable. Not sure what I'm doing wrong. I will probably just hand in my answer as is and see what they wanted me to do - many thanks everyone. I...
I thought there is a specific one for hydrogen and different ones for each element? It says this here: http://scienceworld.wolfram.com/physics/RydbergConstant.html
Have I misunderstood - please can you explain?
I can't see how the rydberg formula would help here as there would be too many unknowns - the rydberg constant and atomic number for the unknown element, and I would still have to make an assumption about the energy levels involved in the absorption.
I think that is another formula - the Rydberg formula, which came before Bohr's formula (which I am using) which proves the Rydberg - but I may be wrong. So i don't think I need to use that one? many thanks