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Homework Help: Work, energy, and power problem

  1. Mar 18, 2010 #1
    1. The Queen Mary 2, whose maiden voyage was in January 2004, is a cruise ship that has a mass of 150,000 gross tons (which equals 1.52×108 kg, about three times that of the Titanic). Her electrically driven pod motors have a maximum power rating of 1.57×105 hp, or 117 MW. (a) What is the kinetic energy of the QM2 when she is moving at 15.0 meters/second? (b) What is the work done by the ships motors to accelerate the ship from 0-15m/s. (c) Find the absolute minimum time in which the ship's engines could accelerate her from rest up to 15.0 m/s. Ignore the drag resistance of the water, air, and so on. (d) What is the force that the ship's propellers exert on the water when the Queen Mary 2 is moving at 15.0 m/s (assume that the maximum power is used)?

    a-ke= 1/2 m v^2
    ke= 1.71 x 10^10

    b= w= ke
    w= 1.71 x 10 ^10

    c- p= w/t
    1.57 x10 ^5= 1.71x 10^10 t
    t= 9.18128655 x10 ^14

    d- no idea.
    Last edited: Mar 18, 2010
  2. jcsd
  3. Mar 18, 2010 #2
    Please show your attempts at answering the question.
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