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Homework Help: Inelastic collision car

  1. Dec 7, 2008 #1
    1. The problem statement, all variables and given/known data

    A 1200 kg car moving at 88 km/h collides with a 7600 kg truck moving in the same direction at 65 km/h. The two stick together, continuing in their original direction at 68 km/h. Determine the kinetic energy of the center of mass of the (car + truck) system. Determine the internal energy of the (car + truck) system before the collision. Determine the internal energy of the (car + truck) system after the collision.

    2. Relevant equations

    m1v1 + m2v2 = (m1 + m2)vf

    Kinetic energy of a system is K = Kcm + Kint

    K = 1/2mv2

    3. The attempt at a solution

    88 km/h converted to 24.4444 m/s
    65 km/h converted to 18.0556 m/s
     
  2. jcsd
  3. Dec 7, 2008 #2

    rock.freak667

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    Homework Helper

    You'd need to find the velocity of the (car+truck) system after collision to get the kinetic energy.
     
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