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Homework Help: Work and displacement problem

  1. Feb 22, 2005 #1
    i think i got a start on this one, but i'm not quite sure where to go!

    problem: a 53.5 kg diver steps off a diving board and drops straight down into the water. the water provides an average net force of resistance of 1552 N to the diver's fall. the acceleration of gravity is 9.81 m/s^2. If the diver comes to rest 4.3 m below the water's surface, what is the total distance between the diving board and the diver's stopping point underwater? answer in units of m.

    so so far, i have found the force of gravity that is working on the diver to be 524.835 N. I know that net work equals the net force times displacement, but i can't find the displacement, because the only thing that i've really solved for is the net force. help!
  2. jcsd
  3. Feb 22, 2005 #2


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    The diver accelerates to some velocity when he hits the water. Then he begins to decelerate due to drag of the water. If you assume that the density of the diver is approximately the same as water, then the bouyancy in the water offsets the force of gravity, so one only need consider the drag in the water.

    The average force of the water resistance is 1552 m, almost 3 times the force of gravity on the diver.

    Think of how force, acceleration and distance relate.
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