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Horizontal veolocity given vertical velocity and angle

  1. Sep 25, 2009 #1
    1. The problem statement, all variables and given/known data
    A person looking out the window of a stationary train notices that raindrops are falling vertically down at a speed of 8.7 m/s relative to the ground. When the train moves at a constant velocity, the raindrops make an angle of θ = 67° when they move past the window as the drawing shows. How fast is the train moving?

    2. Relevant equations
    Vx = V0x +axt

    3. The attempt at a solution
    3.4 and 22.3 m/s are both incorrect.

    Couldn't figure out how to do it since clearly you don't just use the Pythagorean Theorem... walk me through it?
  2. jcsd
  3. Sep 25, 2009 #2


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    Science Advisor
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    Hi IAmSparticus! :wink:

    You'd only use Pythagoras if you wanted the length of the third side.

    But you only want the angle … so use cos or sin or tan. :smile:
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