# Search results

1. ### Calculate Accuracy of GPS?

Hello, I need to calculate how accurate a GPS system is using only Special Relativity and a very basic knowledge of GR (without tensors...which is limited). I'm not sure where to begin however... where does the uncertainty in the measurement come from? How can I calculate the size of the...
2. ### Special Relativity - Help Please!

The 7 years is as measured by the traveling twin's frame. So my intuition wants to say that his return is 14 years in his frame. However I think that this may be flawed due to lorentz contraction of the distance being traveled.
3. ### Special Relativity - Help Please!

Homework Statement Two twins start their clocks at the same time, one of them travels for 7 years at a speed of 4/5c, reverses direction and returns at half the speed. The other twin remains stationary, what is the difference in their age? Homework Equations t = t_p γ The Attempt...

5. ### Compton Scattering Concept Question

Hi, I had an issue with compton scattering that I never received a satisfactory answer for. My issue was that after the collision, there exists a y component of momentum... but all diagrams of the compton effect align the axis center to center from the photon to the electron and on top of...

Thank you!
7. ### Infinite Series

Thank you micromass, I'll try expanding that out as soon as I get home. I'm sure it'll telescope out... there is one thing driving me nuts however. \sum 1/n is a harmonic series... which is divergent. I'm not sure about \sum 1/(n+k) since series have the property that \sum (a-b)=\sum...
8. ### Infinite Series

\sum\frac{1}{n(n+k)} from n=1 to infinity find that the series is convergent and find it's sum. Now I'm a bit confused... I can show it's convergent with k=1 and I attempted the same thing with k by breaking this into partial fractions. But I'm given a harmonic series that is divergent...
9. ### Whether the boy can catch the ship? relative velocity

Direction should affect your time traveled by the boy, and thus your velocity of the boat. Maybe you found a way the angles cancel out to an identity? I'm not sure I'm just considering the problem in my head.
10. ### Shopping Carts, Finding Horizontal Force

This problem is easier if you rotate your axis 13 degrees. So draw the x axis to be parallel with the acceleration. With your current axis ... Fx = F and don't forget your normal force and force due to gravity. Now, if you redraw your axis along the direction of acceleration Fx = Fcos(13)...
11. ### Whether the boy can catch the ship? relative velocity

Hmmm, since it doesnt say anything about the boy's direction when he starts swimming I assume they want you to consider a right triangle...of course this depends on your level of physics class also... if you find this is not the case then use the law of cosines to solve the problem . Consider a...
12. ### Finding Lorentz Vector? -Physics Noob

Thank you so much tim. I was thinking of the angle from psuedorapidity in terms of the Pz vector component and not of the total momentum! Thanks!
13. ### Finding Lorentz Vector? -Physics Noob

I was given this as an extra-curricular activity... way over my understanding of physics, sophmore year undergraduate. But I can use a bit of help. I'm given data from a collision resulting in 2 muons. (this is exactly how the text is written to me, if any of these definitions are not...
14. ### Mass reconstruction

sorry, I'm going to have to verify in layman's terms.. this is way above my current education in physics. (sophmore year undergrad) So what you're doing is analyzing the decay products, summing up their total energies to trace back the energy , and thus the masses, of their parent particles?
15. ### Mass reconstruction

What is it? I always hear it and never know what exactly it means to "reconstruct" mass.
16. ### Computational Physics

Hi, Im an undergrad physics student and trying to get a research position at my school. I've talked to one researcher and he didn't have a use for me but advised me to look into computational physics work with another professor. What is computational physics exactly? I know that you can...
17. ### Non-Uniform Dielectric

Thank you tim!
18. ### Non-Uniform Dielectric

This isn't a homework problem, just something to explore my understanding so correct me if any of my assumptions are wrong. I have given myself the situation where I have a capacitor of area "A" and separation "d" Between them is a non-uniform but continuous dielectric, so that the...
19. ### Capacitors, energy storage and energy release

Just a short concept question for understanding... I understand that a capacitor stores a charge, However I'm told that capacitors can be used to store up a charge and release it very quickly. How does this energy get released is what I don't understand. To my understanding of a...
20. ### Work problem 2

What is work? Work=\int F ds From this you can find that Work=-\Delta U and Work=\Delta KE Read your book about work and energy.
21. ### Quick Couple Concept Questions on Guass's Law

Thanks a bunch ehild!
22. ### Spring pushing block down and up hill problem

I haven't checked for myself if your numerical answer is correct or not. Don't think of any picture in energy problems to be necessarily to scale, think of h as a changing variable, so it could easily stretch way up or even stretch below the point you call h=0. It might help you in other...
23. ### Spring pushing block down and up hill problem

No, not JUST spring potential. But you must include spring potential. You start out not moving, you don't have any kinetic energy initially. The question says after the block runs into the second spring it compresses 2.1 m before being shot out the other way. So your final kinetic energy is...
24. ### Work problem 2

what's making the paratrooper fall? Force by gravity. So to stop him what force must be applied? Think of newtons third law. What is work? work is force times distance. The distance is the depth of the crater, what is the work?
25. ### Work problem

I think your equations may be confusing you. For instance what is h? h or (d) should be the distance that the cyclist is traveling. so h=d sin (6) make sense? now W = -\Delta U so if you call your initial position h=0 your final potential is mgh now can you use d to solve for velocity?
26. ### Spring pushing block down and up hill problem

Well you should know that KE_{i} + U_{i} = KE_{f} + U_{f} This is equivalent to saying that energy is conserved. So Kinetic Energy initial + potential energy initial is equal to Kinetic Energy Final + Potential Final. A spring is just potential energy. Energy is stored in the spring...
27. ### Quick Couple Concept Questions on Guass's Law

Just a couple quick questions I was wondering about. Also, this is an Introductory E&M class so we don't actually perform the surface integral so knowing \oint\vec{E}d\vec{A}=EA=\frac{q_{enclosed}}{\epsilon_{0}} When using cylindrical symmetry I'm supposed to ignore any flux on the top and...
28. ### Finding E field from potential

Thank you rl.bhat I took a look at the lamba again and figured out I should have simply just solved for lamba instead of q using my potential integration. Thanks!
29. ### Finding E field from potential

Well I can't possibly answer with that solution though. I know nothing about the length of the cylinder except that it is very long. To answer in terms of lamba would be an incomplete answer since I still have unknown variables.
30. ### Finding E field from potential

Two long conducting cylindrical shells are coaxial and have radii of 20 mm and 80 mm. The electric potential of the inner conductor, with respect to the outer conductor, is +600V. In the situation provided, an electron is in circular motion around the inner cylinder in an orbit of 30mm...