Recent content by Ravenatic20

  1. R

    General relationship for direction of E field at any given point

    I was going through my textbook, Introduction to Electrodynamics, and I came across this question that puzzled me. The book is really great by the way, I would highly recommend it. No, this isn't a homework question, it just got me thinking. For a finite line of charge (like a rod, for...
  2. R

    Observed lifetime of muons (relativity)

    I found out what I was doing wrong. It's really stupid. When solving for N, my value for tau(7.04 microseconds), I didn't punch it into my calculator right. Was entering 7.04 instead of 7.04X10^-6. The answer I got then was right, about 1.13X10^4. Mark this problem as solved. Thanks...
  3. R

    Observed lifetime of muons (relativity)

    Dick, thanks for catching that gamma is dimensionless. If anyone has any last minute ideas please post them. Thank you.
  4. R

    Observed lifetime of muons (relativity)

    I apologize for the shameless 'thread bumping', but I'm really stuck on this problem and could use some help. It's due in about 12 hours so that's why I'm rushing now. I don't like turning in HW I know is wrong.
  5. R

    Observed lifetime of muons (relativity)

    Homework Statement The muon is an unstable particle that spontaneously decays into an electron and two neutrinos. If the number of muons at t = 0 is N_{o}, the number at time t is given by N = N_{0}e^{-t/\tau}, where \tau is the mean lifetime, equal to 2.2 \mu s. Suppose the muons move at a...
  6. R

    Show momentum is conserved in two different frames (relativity)

    You're right. I ended up solving the problem. Thanks anyways. Consider this problem solved.
  7. R

    Show momentum is conserved in two different frames (relativity)

    Homework Statement A 2000-kg car moving with a speed of 20 m/s collides with and sticks to a 1500-kg car at rest. Show that because momentum is conserved in the rest frame, momentum is also conserved in a reference frame moving with a speed of 10 m/s in the direction of the moving car...
  8. R

    Showing acceleration is constant

    Thank you. I always over complicate things. I believe I know how to do it now. To answer your question, y is -b\omega^2\cos(\omega t) and z is 2c Now I square them, add them up, and take the square root of that sum (this:||\mathbf{a}||=\sqrt{a_x^2+a_y^2+a_y^2}). Correct?
  9. R

    Showing acceleration is constant

    So I take \mathbf{a} (the second derivative above), and factor in x for the first part. So it would look like this: \mathbf{a_x}(t)=[-b\omega^2\sin(\omega t)\mathbf{i}-b\omega^2\cos(\omega t)\mathbf{j}+2c\mathbf{k}*\mathbf{b}sin(\omega t)]^2, where \mathbf{b}sin(\omega t) is x. Then do...
  10. R

    Showing acceleration is constant

    Thank you guys :) Now what is the first step in calculating the magnitude? I am used to plugging in numbers to do that.
  11. R

    Showing acceleration is constant

    The first derivative: ib\omega cos \omegat - jb\omega sin \omegat + 2kct Second derivative: -ib\omega^{2} sin \omegat - jb\omega^{2} cos \omegat + 2kc Is that right?
  12. R

    Showing acceleration is constant

    I hope I posted in the right place. Sorry in advanced. Homework Statement A buzzing fly moves in a helical path given by the equation r(t) = ib sin \omegat + jb cos \omegat + kct^{2} Show that the magnitude of the acceleration of the fly is constant, provided b, \omega, and c are...
  13. R

    Is this integration probelm right so far?

    \int_{e}^{infinity} \frac{dx}{x \ln x} = \int_{e}^{infinity} \frac{1}{x \ln x} dx = \int_{e}^{infinity} \frac{1}{\ln x} d \ln x = ln|lnx| + C evaluated from e to infinity I think I know what I need to do next, I just want to make sure I'm good up to this point. Also, how do you put in an...
  14. R

    Can You Solve This Integration Problem with a Little Help from Trigonometry?

    Haha no offense taken and thanks for your help!
  15. R

    Can You Solve This Integration Problem with a Little Help from Trigonometry?

    No I'm not drunk, I'm just new to this material. However I think were just about done: I understand how you did everything, so now... 4\int(\sec \theta \tan \theta) \tan \theta d\theta=4(\sec \theta \tan \theta-\int\sec^{3}\theta d\theta) Where... \int\sec^{3}\theta d\theta) =...
Back
Top