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Homework Help: What is the net impulse?

  1. Jun 17, 2010 #1
    1. The problem statement, all variables and given/known data
    A person with a mass of 80.6 kg jumps from a squat position into the air. The velocity
    at the beginning of the jump is zero. Fast motion video analysis reveals that the
    velocity of the centre of mass at take-off was 5.3 ms-1. Foot contact time when the
    ground reaction forces are being generated is 0.25 s. What is the net impulse?

    2. Relevant equations

    I = change in p
    p = m * v
    I = F * t

    3. The attempt at a solution

    80.6 * 5.3 = 427.18
    427.18 * 0.25 = 106.8

    Can someone please check this, I think I've made a mistake

    Thanks heaps =)
  2. jcsd
  3. Jun 17, 2010 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Re: Impulse/Momentum

    This is all you need.

    Why don't you describe what you were doing in each of these calculations? (One makes sense, the other doesn't. :wink:)
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