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Homework Help: Relativity Problem

  1. Sep 4, 2011 #1
    1. The problem statement, all variables and given/known data

    You point a laser flahlight to the Moon, producing a spot of light on the moons surface. At what minimum angular speed must you sweep the laser in order for the light spot to streak across the moons surface with speed v > c? Why cant you transmit information between research bases on the Moon with the flying spot?

    2. Relevant equations

    3. The attempt at a solution

    The problem is utilizing the correct length. I measure it smaller then it is, since im so far away. but is there a way to calculate that?
  2. jcsd
  3. Sep 5, 2011 #2
    V = omega x R

    V = c
    R = about 380,000 km
    omega = angular velocity in radians/s

    For the second part think how you might use the laser on Earth to allow different moon bases to communicate.
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