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Determine speed of bar and average frictional force

  1. Feb 21, 2012 #1
    1. The problem statement, all variables and given/known data
    Large metal bars can be driven into the ground using a heavy falling object. What I have here is a 2000 kg falling object and a metal bar of 400 kg. The falling object strikes the bar at a speed of 6.0 m/s. It comes to rest on the bar without bouncing. As a result of the collision, the bar is driven into the ground to a depth of 0.75m
    Now, I need to determine the speed of the bar immediately after the object strikes it
    and determine the average frictional force exerted by the ground on the bar.

    I'm just not sure on how to approach this.
    I kind of have an idea of finding acceleration first for the frictional force which is F= ma?
  2. jcsd
  3. Feb 21, 2012 #2
    you need to find the force in which will make a item of that mass be driven to that depth. i think you can find depth as the same as distance
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