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Homework Help: Problem CAR

  1. Jun 28, 2009 #1
    A car of 1200 kg pull a trailer of 1050 kg. The set is moving at 90 km/h suddenly suffers the action of the brakes. Knowing that the forces of officers in the car brakes on the trailer and worth 4500N and 3600N, respectively, determine (a) the deceleration of the joint and (b) the horizontal component of force exerted by the trailer on the car

    I think:


    ZFx = mc . a
    -Ftc = mc . a


    ZFx = mt . a
    Ftc = mt . a

    But not possible to calculate
  2. jcsd
  3. Jun 28, 2009 #2


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    Homework Helper

    What is the deceleration of the combined system?

    ∑F = (∑m)*a

    a = ∑F/∑m

    Then, knowing the deceleration of the whole, draw a force diagram to figure the forces between the parts.
  4. Jun 28, 2009 #3
    Thank you.

    a = (4500+3600)/(1200+1050) = 3,6 m/s^2

    Break + F = mB . a
    F = (1050 x 3,6) - 3600
    F = 180 N
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