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Homework Help: Kinetic energy

  1. Oct 8, 2005 #1
    Hi I have a problem here and I am a little bit confused.

    An object of mass 0.23kg is initially at tyhe origin and is acted on by the sole force F=(0.50 N)i. After a certain time, the object is at a position r=(.88m)i.
    What is the change in the object's kinetic?


    I tried to solve this problem by th equatiom Wnet=K, but I do not get the answer of the textbook. They found .89m/s .Apparently,it v. They did not specify.

    Please can youhelp

    Thank you for your time
    B
     
  2. jcsd
  3. Oct 8, 2005 #2

    HallsofIvy

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    Sorry, this makes no sense to me! If the object moves .88 m under a .5 N force, then it has had .44 J of work done on it. It's kinetic energy should have changed by .44 J. If, as you say, that was the sole force then we should have (1/2)(.23 kg) v2= 0.44. that gives v2= 0.88/.23= 3.8 so v= 1.9 m/s.
     
  4. Oct 8, 2005 #3
    Yes, I found the same result as you.
    I must have a typo in my textbook.
    Thank you anyway

    B
     
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