Recent content by capslock

Hi guys, I'm hopelessly stuck on a couple of quantum questions. Any guidance would be very much appreciated! (1) According to Bohr's theory, what would be the four longest wavelengths of light that can be absorbed by a stationary hydrogen atom initially in its ground state? If an atom absorbs...

Many thanks.

But how do I use the information given to calculate it? Best Regards, Jonathan.

That's great. Thanks.

When middle C on a piano (frequency = 262Hz) is struck, the vibration of the piano string loses half its energy after 4s. (i) What is the decay time for the energy? (ii) What is the Q-factor for this piano wire? (iii) What is the fractional energy loss per cycle? SHM has been going great...

I'm trying to calculate the pressure of outer space given the denisty of helium is of the order 1 atom per cm^3, temprature 3K. 1 atom per cm^3 => 10^6 per m^3. It's a low pressure so I guess I can use the ideal gas equation. I also know the mass of a helium atom is 6.68x10^-27 kg...

LF equations? I'm working from the Lorentz equations. How do I derive them? Best Regards, James

Dear All, Have a small problem: Two chaps attempt to demonstrate the phenomenon of Fitzgerald-Lorentz contraction. The two meet at the centre of a fast train which is L = 500m long and traveling at a speech of u = 0.7c to synchronize their watches. One sits at the front of the train while the...

I have the equation for the Morse potential, U = E_0 (1-exp(-a(r-r_0))^2. I'm asked to show that near the minimum of the curve the potential energy is a parabolic function. I've tried to play around with the taylor series with no hope! :( :( Many thanks, James

A rocket travels from Earth to the moon (distance measured from the Earth 384000km) at a speed v = 0.8c. (i) How long does it the trip take according to an observer on earth? Just used straightforward Newtonian mechanics, t = 384000*10^3/(0.8*3*10^8) = 1.6s. (ii) How long does the...

A glass hydrometer of mass m floats in water of density p. The area of the neck of the hydrometer is A. The resonant frequancy for the vertical oscillations of the hydrometer is given by f = (1/2\pi) (Apg/m)^(1/2) Calculuate the fractional change in the resonant frequancy when the...

I have derived expression for the heat flow along a bar with cross-sectional area A, given by 'Q = -KA dT/dx' where K is thermal conductivity constant and T and x refer to temperature and distance measured from the high temperature end of the bar. I understand this. My problem is when I try...

Was it the article on the Poincaré conjecture? That was really facinating. Can anyone recommend a good undergradate text in toplogy?

They often have silly mistakes though and sometimes I find the material to be quite ambiguous. If you are looking for a very thorough guide for 'A' level Pure Mathematics I would recommend: Mathematical Techniques: An Introduction for the Engineering, Physical, and Mathematical Sciences...

It is the 19th I believe :) Waiting for my Phyiscs A2/Mathematics A2/Further Mathematics A2/Philosophy A2/STEP results! Roll on!