Recent content by jono90one

Hi, I have a question regarding pair production, regarding the amplitude that I am trying to understand. I have attached a photograph of the feynmann diagram, which I believe to be correct - although I don't like the vertex/propogator combination as shown below: (I have split up integral so it...

Hi, I am just trying to understand the connection between these two things. As far as I understand it: BAO - Before decoupling the baryons were in thermal equilibrium with photons and as a result this gave rise to a pressure force. But given in regions of high dark matter density baryons are...

In terms of the LHS I did, \hat{P}|a> = (+1)(-1)(-1)^{L} = (-1)(-1)^{0} = -1 \hat{C}|a> = (-1)^{L+S} = (-1)^{0} = +1 \hat{C}\hat{P}|a> = (-1)(+1) = -1

Hi, I am currently going over this and got me thinking about a scanario where you have A -> BC Where A is S = 0, L=0, B is S = 1 L=0, C is S=1 L =0 (I'll use S = intrinsic spin, L = angular momentum, J = Total Angular momentum, |L-S|=< J =< L+S) Maybe such a decay doesn't exist, but I'm just...

Hi, I am just learning some materials and struggling to find what the other octet is. I know the following: 3 \otimes 3 \otimes 3 = 10 \oplus 8 \oplus 8 \oplus 1 Now I understand the 10 and one of the 8's. But I am a little unsure of what the other octet and singlet is in terms of quarks...

Ohh i see where i went wrong lol. I now get 0.518 for the value of eta :D Thanks!

Homework Statement I have been doing an experiment, and I needed to calculate the value of η for a diode. The value should be between 0.5 and 1.0... The value for alpha obtained is 20. Homework Equations αV=ηeV/kT Where k is Boltzmann’s constant, eV is the electron volt, T is...

(edit) So you mean f=v/T(vs-v)??

Homework Statement A sound source moves at a constant velocity. A listener is standing at a distance L away from it. Given that the source moves in a straight line at a right angle to the listener and starts closest to the listener (ie at t=0) deduce an expression for the frequency heard by the...

Homework Statement Adjacent anti-nodes of a standing wave are 7m apart. The amplitude is 0.5m and period 0.05 seconds. Assuming the string is clamped at the position x=0m, y=0m on the left hand side. Find the amplitude at the point 0.29 m from the right of an antinode Homework Equations...

Oh ok, just out of interest, is there a method with integration for this circumstance?

Thanks for the responce, well from what i ahve been taught, i can work out the moment of inertia via integration. Though I am not 100% sure whether i can use the exact same method of the mass isn't uniform. But the basis of the second method is work out the mass of a small piece = (m/l) δx...

I have a question but got two different answers by two different methods. The question: "Two workers are holding an 80kg plank, one worker let's go. The weight is carried by 55% of the first worker. It is 2.5m long and no uniform. The angular acceleration is 5.5 rads/s^2, what is the moment of...

Homework Statement A slope angled 36* to the horizontal has a hoop cylindrical shell going down it, which has radius 3cm and mass 100g. 1) Write down an equation of motion for the angular acceleration. 2) Will the linear acceleration change if the hoop is changed to a cylinder (i.e...

for "r" in mr^2 is it the shortest distance? (consider a square with point mass at the corners connected by rods, r is closer if you take the diagonal height rather than the rod distance.)