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Homework Help: Help for biomechanics question

  1. Apr 26, 2009 #1
    urgent help for biomechanics question

    the question that im not sure of is:
    A body of mass 9.4 kg initially moving in a straight line at 3.7 m/s is acted on by an accelerating force of 36.5 N (in the same direction as initial motion) for 1.32 seconds Calculate the velocity of the body at the moment the applied force ceases. Express the units in symbol form in the space provided.

    when i sorted it out i found acceleration first a=0-3.7/1.32= -2.80
    then i had to find final
    vf= 3.7+-2.80 x 1.32= my calculator came with 4.e-03 which is 0.004, however i did it another way and made acceleration positive and got 7.40.
    but the one thing that im concerned is that i have not inputed the newtons and kilos in this equation :(
    your help is greatly appreciated :)
  2. jcsd
  3. Apr 26, 2009 #2


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    Re: urgent help for biomechanics question

    That's not the acceleration. The acceleration due to a force F is a = F/m.
  4. Apr 26, 2009 #3
    Re: urgent help for biomechanics question

    so if i use that formula i did 36.5/9.4= 3.88 then used that to find final
    vf= 3.7+ 3.88x1.32= 8.72m/s

    it was sorta getting to me because there was a similar question but it did not give us the force in N but it gave the mass, time, final velocity, with that i found acceleration with using vf-vi/time and then times it by the mass. but seeing how you expressed the formula and how i see it varying with the other question makes sence
    thanks heaps :)
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