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Homework Help: Relative velocity of rain to car

  1. Sep 30, 2008 #1
    1. The problem statement, all variables and given/known data
    Hi, I've been trying to do this problem with limited success. If someone could help me realize where I went wrong, I would greatly appreciate it

    Assume the downward direction is positive. A car travels due east with a horizontal speed of 53.7 km/hr. Rain is falling vertically with respect to earth. The traces of the rain on the side window of the car make an angle of 61.3 degrees with the vertical. a) Find the magnitude of velocity of the rain with respect to the car. b) Find the magnitude of the rain's velocity with respect to earth.

    This is what I did: After drawing a picture, I saw that the rain makes a triangle with the side window of the car, so I did 53.7tan(61.3) to get A. For b i used the pythagorean theorem.
  2. jcsd
  3. Sep 30, 2008 #2


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    Hi Maiia! :smile:

    The velocity of the rain with respect to the car is the hypotneuse, isn't it?

    You used tan, which is opp/adj.

    Try again! :smile:
  4. Sep 30, 2008 #3
    Ohhh I get it now! I got the velocity with respect to car and velocity wrt to earth mixed up -.- Thanks a lot for your help :)
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