Homework Statement
I have a relativistic electron with energy 10^10 eV and I want to work out its speed. I'm not told if that's total energy or just kinetic energy - which is the sensible assumption to make?
Homework Equations
(E_tot)^2 = p^2*c^2 + m0^2*c^4
p = gamma*mv
gamma =...
Ok, I think I've solved this now. I'm just not sure about one of the steps I used to get to the answer.
I assumed that the normal component of the electric displacement D is continuous at the boundary, and hence
\epsilon_{1} = - \epsilon_{2}
Bearing in mind that the boundary is between...
We've always had rescue cats, all mongrels. By my reckoning, about half of them would be there to greet us when we came in, squeaking and rubbing against us. The other half didn't, but they too enjoyed our company and attention - despite their reputation, cats require more than just feeding to...
Homework Statement
Consider the plane interface z=0 between metal 1 at z>0 and metal 2 at z<0. Metal 1 has bulk plasmon frequency \omega_{p1}; metal 2 has \omega_{p2}. The dielectric constants in both metals are those of electron gases. Show that surface plasmons associated with the...
Well I did try that, but the percentages I got were so small that I wondered whether I'd done the calculations right...
I found that:
(1.01e-32)% of oxygen atoms (yes I mean atoms not molecules, as in the Earth's upper atmosphere),
(8.99e-7)% of helium atoms,
and 0.00016% of...
The Earth's atmosphere is lacking in gases like hydrogen and helium because at a given temperature, a 'significant fraction' of hydrogen or helium particles have speeds greater than Earth's escape speed, while gases like oxygen only have a 'negligible fraction' of the total number of particles...
So there is no one definition for 'accuracy' but using the standard deviation as a value for accuracy is acceptable?
Right, now I know what the question is asking! Thank you.
I'm not sure I understand you. Are you saying that the standard deviation of the mean is the standard deviation of the data divided by root N? Is that the accuracy? I don't know what is meant by 'accuracy' in this context.
I've got nine sets of data (three people each took ten measurements of three different distances), and I need to find an estimate of the accuracy to which each person measured each distance.
I've already calculated the mean and standard deviation for each set of data, but I don't know how to...
Oh right, but does it matter if I use pseudo forces to solve this kind of problem, since it gets me the same answer for a? Is it just a matter of preference or should I be looking at the real forces instead?
I just tried it again adding the accelerations as vectors and got T = 1.62s, so...
"As your jet plane speeds down the runway on take off, you measure its acceleration by suspending your yo-yo as a simple pendulum and noting that when the bob (mass 40g) is at rest relative to you, the string (length 70cm) makes an angle of 22 degrees with the vertical. Find the period T for...