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Homework Help: Relative velocity of grenade

  1. Sep 22, 2008 #1
    1. The problem statement, all variables and given/known data
    In an action-adventure film, the hero is supposed to throw a grenade from his car, which is going 91.0 km/h, to his enemy's car, which is going 106 km/h. The enemy's car is 14.5 m in front of the hero's when he lets go of the grenade.

    a)If the hero throws the grenade so its initial velocity relative to him is at an angle of 45 above the horizontal, what should the magnitude of the initial velocity be?

    b)Find the magnitude of the velocity relative to the earth.

    2. Relevant equations
    Vh/r=90 km/h
    Ven/r=110 km/h

    3. The attempt at a solution

    a)I have no real idea on how to proceed with this problem. The real thing that is confusing me is the inclusion of the 14.5m and it can be used in calculating the initial velocity.

    Any help is as always much appreciated.
  2. jcsd
  3. Sep 23, 2008 #2


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    Hi anubis01! :smile:

    You need to use x1 for one car and x2 for the other car, and x1(0) = 0 while x2(0) = 14.5. :wink:
  4. Sep 23, 2008 #3
    ah I see, I get it now. Thank you for the help.
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