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Quick question about energy

  1. Dec 18, 2007 #1
    When they say K=1/2mv^2 does K mean the change of kinetic energy? because Wtotal= the change of kinetic energy...
  2. jcsd
  3. Dec 18, 2007 #2
    1/2 mv^2 gives the kinetic energy of an object with mass m moving with velocity v. To find the change in kinetic energy, one would have to solve for Kfinal - Kinitial, which would be equal to the Wtotal of which you speak.
  4. Dec 25, 2007 #3
    to calculate change in K.E we have formula 0.5*mass*(v*v-u*u)......
    think about potential energy
    we can calculate only change (d)
    and arbitarily assume U at some point and express potential energy as
    actualy we can perform only relative analysis
    and therefore diff of K.E of a moving body velocity v with respect to body at rest can be obtained by substituting u=0..

    but to calculate absolute K.E we must take an arbitarily some value of K.E for body at rest...and then add it to the difference

    and so what do you think is most appropriate, logical & convinient value to be given to the body at rest .?????????????????????

    well your question was good but a bit vague inexpression I think..:smile:
    Last edited: Dec 25, 2007
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