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Homework Help: What force ?

  1. Oct 3, 2007 #1
    A 5 g bullet leaves the muzzle of a rifle with a speed of 320 m/s. What force (assumed constant) is exerted on the bullet while it is traveling down the .82 m long barrel of the rifle ?
    m = .005 kg
    v (initial) = 320 m/s
    d = .82m

    F = ma
    but i don't know how to find a

    The parachute on a race car of weight 8820 N opens at the end of a quarter-mile run when the car is traveling at 35 m/s. What total retarding force must be supplied by the parachute to stop the car in a distance of 1000m?
    d = 1000m
    Totally got no idea

    Help please ? I am sick in these day, so my mind not really on it !
    Last edited: Oct 3, 2007
  2. jcsd
  3. Oct 3, 2007 #2
    Willingtolearn -

    You must show some sort of work or indicate where you are stuck to receive our help.
  4. Oct 3, 2007 #3
    Totally got no idea
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