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Quick help on this

  1. Oct 16, 2007 #1
    1. The problem statement, all variables and given/known data
    One 105 kg football lineman is running to the right at 2.55 m/s while another is 130 kg lineman is running directly toward him at 2.80 m/s.

    What is the total kinetic energy?

    2. Relevant equations
    ok, so K=1/2mv^2

    3. The attempt at a solution

    So, I found the kInetic energy for both of them and just added them together.
    K1. K= (.50)(105kg)(2.55m/s)^2=341.38J

    K2. K= (.50)(130kg)(-2.80m/s)^2=539.14J

    So, I added them together and I got 880.52, which is not the answer and it keeps telling me that I have some sort of rounding error. Please help!!!!!!!!!!!!!!!!!!!1
  2. jcsd
  3. Oct 16, 2007 #2


    User Avatar
    Homework Helper
    Gold Member

    If I am reading the question correctly, you are being asked for the total kinetic energy of both linemen. If this is correct, then I agree with your answer. Try putting the numbers in the calculator again and this time don't round off at all if you did before. (Computer homework systems can be a pain sometimes.)
  4. Oct 16, 2007 #3
    i copied the wrong number when I was doing the calculations.. Thanks though.. I know I hate this Mastering Physics....
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