1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Simple geometrical problem

  1. Apr 20, 2008 #1
    Does anyone can help me how to find [tex]r * sin \theta * d\phi[/tex] (please see attached image)?

    Here some other that I can solve:

    FIRST

    [tex]d\theta = L / r[/tex]

    so

    [tex]L = r * d\theta[/tex]

    SECOND

    [tex]sin \theta = P / r[/tex]

    so

    [tex]P = r * sin \theta[/tex]

    THIRD

    [tex]d\phi = B / r[/tex]

    so

    [tex]B = r * d\phi[/tex]

    FOURTH

    The pink-hatched region is a regular rectangle with length L and width W.
    So the area of this rectangle denoted by dS is:

    [tex]dS = width * length
    = (r * sin \theta * d\phi) (r * d\theta)
    = r^2 * sin \theta * d[tex]\theta * d\phi[/tex]

    Also, how to obtain [tex]d\omega = dS / r^2[/tex]?

    Thanks in advance
     

    Attached Files:

  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted



Similar Discussions: Simple geometrical problem
  1. Simple problem (Replies: 6)

Loading...