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Homework Help: Substended angle, diameter question

  1. Sep 18, 2011 #1
    We are on lesson 1 and 2, which are vectors and kinematics only. We haven't covered anything else, yet the professor assigned us this problem. Can anybody help me? I have searched google and have yet to understand this problem. Thank you!

    To an observer on earth, the moon, which is 3.8x10^5 km away, substends an angle of 0.52 degrees. What is the moons diameter?

    2. Relevant equations
    I found on google that S=R x theta

    3. The attempt at a solution
    The answer is 3500 km, but no matter what configuration I put these values into the equation, I still don't get the right answer.
  2. jcsd
  3. Sep 18, 2011 #2
    I think you have to convert the angle in degrees to an angle in radians for the formula to work? Try that.
  4. Sep 18, 2011 #3
    thank you! yes that works!!!
  5. Sep 18, 2011 #4


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    Last edited by a moderator: Apr 26, 2017
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