Recent content by geoffreythelm

Homework Statement http://img687.imageshack.us/img687/7963/screenshot20120102at185.png Homework Equations The Attempt at a Solution I understand how to compute a Chi-squared test, but I'm a bit confused about the wording of parts a) and c). Could someone possibly simplify it for...

Homework Statement Consider the wave described by: E= 3 sin [pi (x/c - t)*10^13+ pi/6] True or false? 34. The frequency = 10E13 Hz. 35. The wavelength = 3E-6 m. 36. The direction of motion: positive x direction. 37. The speed = 300 000 km/s. 38. The maximum amplitude = 9...

Thanks for the help, ehild! I've found a formula in my notes for resultant amplitude of 2 waves: (A3)^2 = (A1)^2 + (A2)^2 + 2(A1)(A2)cos(δ) So using this, I get an (A3)^2 of 34, which I suppose is the relative Intensity. Not sure how I should answer this on the question though, I haven't...

I'm getting so confused about this question, any help would be great. :) Homework Statement Two infinite waves Ψ1, Ψ2 have the same wavelength and polarisation and have amplitudes of E1 = 3 and E2 = 7 units. They are added together with a phase difference of 125 degrees. 1) What will be the...

Homework Statement This is a question on a past paper of a second-year undergraduate physics paper. A parallel plate capacitor is charged and the voltage increases at a rate of dV/dt. The plate radius is R and the distance between the plates is d. (a) What is the electric field...

Homework Statement For the following subset W of R3 determine whether or not W is a subspace of R3. If the subset is not a subspace give a specific example to indicate why it is not a subspace. ii.) W = {(x,y,z): 2x + y + 3z = 0 The Attempt at a Solution I know how to do this...

Homework Statement Homework Equations The Attempt at a Solution I think Graphite is a Van der Waals' Solid and, er, salt would be an ionic. But I really don't have much of a clue about what the second part is going on about! Thanks! :)

I see.. So one (the first term?) is due to the attractive force from one ion, and vice versa for the other? So c is going to end up being something which looks like electric potential should. So is the point of equilibrium the point between the ions where the first term= the second term?

Hi, I am having trouble with the following: All I have really done is differentiate the function to give an expression for F(r), but I am a bit clueless about the rest. How can there be equilibrium if the two ions are attracted to each other? Cheers, GeoffreyThelm

Hi. Although this is a rather non-sensicle question, I believe it is one that Einstein posed to his teacher when he was at school: What would the Earth look like to someone who had 'hitched a lift' towards the Earth on the back of a photon? In the frame of reference of the light traveller...