Recent content by timhunderwood

ah got it now thanks very much

I'm having trouble calculating the position of the second image charge. I tried putting it at an arbitrary distance from the centre on line with the other image particle. Then I try to calculate the field due to all three particles at the radius of the conductor. But I think I'm making a...

Homework Statement A point charge q is held a distance d > a below the centre of a large spherical conductor of radius a. Show that, if the spherical conductor is earthed, the potential outside the sphere may be found by placing an image charge at a distance c=a2/d from the centre of the...

Thats good, I mistyped my last equation- it should have read R^4. Thanks for the help

Homework Statement First part of the problem was to work out E-field of uniformly charged spherical shell with charge Q and Radius R. This was fine : E = 0 for r<R and E = Q/(4*Pi*eps*r2) for r>R QUESTION: Find the pressure exerted on the shell due to the charges on its...

Thank you very much, this gives the right answer... However, could you explain why? I don't think I really understand why the impedance at that point should be considered as the parallel combination of Zc and Zs, although I recognise that the circuit looks like resistors in parallel...

Homework Statement An annular sheet (i.e. a flattened ring) , of thickness t = 1mm and made of a material of resistivity 0.5 Ohm m connects the inner and outer conductors of an air spaced coaxial transmission line at a point on the line. A low frequency signal is fed into one end of the line...

Hi I am working on a project and have been slightly side tracked. I want to examine a graph which has a turning point when y=0 (like y=x^2) however it most be insoluble analytically (i.e. a quintic or above). Can someone give me an example of one or tell me a method to generate one. I...

i tried using change of momentum = impulse but I only need to use lambda or Power not both so i think I'm doing something wrong can someone show me a solution. Thanks

Hi I'm a student in school and I'm having a mental block on how to do this question. Could some give me a hint as to the principals I'm meant to consider /use. Q) A red, 100mW, laser beam , wavelength 650nm, is incident normally on a perfectly black disk . Calculate the force on the disk...