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Thread: kinetic energy

  1. #1
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    kinetic energy

    http://www.thephysicsteacher.ie/Exam...s/2009%20b.pdf

    could someone explain to me why in the third part of the question for finding out the kinetic energy of sphere A they do not get the speed of sphere A. they just square the i component and the j component. should they not do this √(u^2/4 +3u^2/400 )
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  2. #2
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    Re: kinetic energy

    Doesn't Pythagoras tell us that the square of the resultant equals the sum of the squares of the components?
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  3. #3
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    Re: kinetic energy

    Kinetic energy is 1/2 mass times velocity squared. There is no point in taking the square root to get velocity when you are just going to square it again!
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  4. #4
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    Re: kinetic energy

    oh ye stupid me
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