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Homework Help: Kinetic energy question

  1. Mar 19, 2014 #1
    1. The problem statement, all variables and given/known data
    I don't know how to solve this question.

    28.8J of work were done in accelerating a mall of 1.8 kg from rest. Find its final velocity. I'm not sure which formula to use..


    2. Relevant equations
    F=ma
    W=Fs
    KE=1/2 mv^2


    3. The attempt at a solution
    I can't figure out which formula to use. (did some working in my workbook)
     
  2. jcsd
  3. Mar 19, 2014 #2

    NascentOxygen

    User Avatar

    Staff: Mentor

    Hi dasher141. http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif [Broken]

    Work and Energy have the same units, so are basically the same thing. I like the formula "work done = change in kinetic energy"
     
    Last edited by a moderator: May 6, 2017
  4. Mar 19, 2014 #3
    A=Wk2-Wk1, Wk1=0 →
    → A=Wk1=mV2/2 → V=[itex]\sqrt{}(2A/m)[/itex]
     
  5. Mar 21, 2014 #4
    Sorry, made a mistake in second line. A=Wk2
     
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