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Homework Help: Power question involving sprinter

  1. Apr 12, 2009 #1
    1. A 50.0 sprinter, starting from rest, runs 56.0 in 9.40 at constant acceleration
    What is the magnitude of the horizontal force acting on the sprinter?
    What is the sprinter's power output at 1.10 , 3.70 , and 5.20 ?

    2. Relevant equations
    I would imagine f=ma and possibly some kinematics for part a, and then P= work/t

    3. The attempt at a solution:
    I cant find the force which seems to be the hardest part
  2. jcsd
  3. Apr 12, 2009 #2


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    Homework Helper

    You know F = M*a, so what is the constant acceleration?

    X = 1/2*a*t2
  4. Apr 12, 2009 #3
    I'm assuming the units on the three numbers in your first line are kg, m, and s respectively?

    You're going to want to find the acceleration a first using one of your kinematics equations. Then identify the mass from your given information and plug m and a into your equation for force.
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