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Homework Help: Kinetic Energy Concept

  1. Jan 10, 2005 #1
    Hello all

    I was just wondering if an object is stationary, how can it still possess kinetic energy? Is it due to the reference frame? Does everthing possess kinetic energy?

    Last edited: Jan 10, 2005
  2. jcsd
  3. Jan 10, 2005 #2
    any ideas?
  4. Jan 10, 2005 #3
    you are right, kinetic energy depends on the reference frame, how? let me show you an example.
    lets say you are in a car which traveling 60mile/hr, and holding a metal ball STATIONARY on your hand, for you, the ball has no kinetics energy, but for me (who standing on the ground), the ball carries a huge kinetics energy, how to prove it? easy, when your car passes by me, throw the ball out and see how much demage the ball will do.....
    conclution: the kinetic energy is depended on the motion of the observer, there are no such thing call absulote kinetic energy,
  5. Jan 10, 2005 #4
    thanks a lot

    just a test:

    [tex] a^{2}+\frac{1}{a^{2}}+2(a+\frac{1}{a})=7 [/tex]
    Last edited: Jan 10, 2005
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