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Homework Help: Kinematics equation problem

  1. Nov 9, 2006 #1
    "An experimental rocket sled can be accelerated at a constant rate from rest to 1600 km/hr in 1.8 s. What is the magnitude of the required net force if the sled has a mass of 500 kg?"

    I know I have to use
    [sum of the] F = ma

    and i was trying
    = 500 x 1600,
    but I'm sure there's something else I have to do to get the right answer, since this isn't working..
  2. jcsd
  3. Nov 10, 2006 #2


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    Science Advisor
    Homework Helper

    Look again at the definition of acceleration. You have used velocity in place of acceleration. Be careful with your units. km/hr is not m/s.
  4. Nov 10, 2006 #3
    If you are having trouble, try solving it in terms of kinematics first. After you find the acceleration, then you can do what you did.
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