# Search results

1. ### Threshold energy particle physics

E(threshold enrgy) = M* − M(squared) −m(squared) divided by 2M Determine the threshold energy for producing a top quark and an anti-top quark when beams of electrons and positrons of equal energy are made to collide head on. What do i sub in where and what do i with M*. Thanks
2. ### Calculate the lattice constant of caesium chloride

Calculate the lattice constant of caesium chloride with ionic radii Cs+ 0.167nm and cl- is 0.181 nm I dont really get it, from all the structures i have seen the distance between one atom and the next is (a) or (a/2) but i dont think im right.Any ideas. What is the difference between the...
3. ### Laws of Time

Would any Laws be violated if time was proven not to be real.
4. ### Density of states (solid state)

calculate the density of states and average energy for an elctron gas in 1d,2d and 3d I know the number of states is N= \int_{0}^{infinity} g(e)f(e) de and E = \int_{0}^{infinity} g(e)ef(e) de and g(e) =dN/de
5. ### Yukawa particle

Hi, i am kind stuck on this question as i don't know what equation to use. doesn't seem to be in any books. By considering possible interactions between protons and neutrons, determine the minimum number of charge states of yukawa's particle. Also why is the interquark force of finite...
6. ### Solid state physics

1 few questions here Does anyone know websites that i can get solid state physics problems and answers. 2ndly How do you show a semiconductor of type 1 behaves as a perfect diamagnet. I know by drawing a diagram but don't how to show it 3rdly what is the...
7. ### Solid state(donors and acceptors)

A sample of silicon contains 10 to the power of 18 donors m3 and 10 to the power of 16 acceptors m3. The donor ionisation energy is 50 meV. Calculate the temperatures at which the electron concentrations are (a) 10 times the saturated value (b) 0.1 the saturated the saturated value...
8. ### Still do rubbish even though i studied for ages.

Could someone please help me, and tell me what i am doing wrong or could do better. im doing a physics degree but this time when it came to exams i studied really hard yet i still couldnt remember everything and in the end i recognised everything but couldnt answer the question. i found...
9. ### How to put magnetic field in the wave equation

Could someone please help, i think this is gauss's law but im not sure how to answer it as they give me a wave equation and i dont know how to put magnetic field in as well. Help would be much appreciated Question suppose that an appropriate device is used to genereate an osccilating...
10. ### Programs With a physics degree only go to a uni where you will be inspired

I am currently at kings college london physics department and have found the biggest reason i am having problems is because when the lecturers speak they dont speak clear and concisely and they usually have a foreign accent and stress there syalubuls incorrectly.This coupled with the fact of...
11. ### How to solve a second order linear homeogeneous ODE with Frobenius?

A simple question i think although i cant find in any books What do u when u are solving a second order linear hoemoeneous differential equation with frobenius and there is no shift. (X^2)(y^{''}) (-6y)=0 it should be normal minus -6y I only know what to do if there is...
12. ### The laplace transform/inverse

Hello can someone please help ive been struggling on this problem for 2 days now. question is calculate the laplace transform of F(P)= 1-P divided by P(squared) + 4P +13 I realise you have to complete the square as denominator is complex When i complete the square i get (P+2) (all...
13. ### Error analysis

i have 5 values of slit width S 0.0015m 0.0158m 0.00191m 0.0021m 0.00257m the standard error is plus or minus 0.0005 however my teacher says she wants us to calculate ∆S error she says its ∆S=S(subscript 2) - S(subscript 1) she says the answer is 0.0007m WHY IS THIS SO...
14. ### Parametric equations

Could someone please give me a clue how to solve these parametric equations or a starting position. torus specified by these equations x=(R+rcosΦ)cosθ y=(R+rcosΦ)sinθ z=rsinΦ calculate the normal to the torus N(θ,Φ) and entire surface area p.s anyone recommend a book or a...
15. ### Differential equation in physics

Hello i have a problem with spherical coordinates however i understand partial differentials. Basically a thin spherical layer of radius R is uniformly charged with surface charge density. Show by Calculating the electrostatic potential (x,y,z) produced by the layer that electrostatic...