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Magnitude of Friction Force Problem

  1. Sep 24, 2010 #1
    1. A car with a mass of 1100 kg is being pulled by a tow truck. The tow truck pulls the car to the north with a constant 1200 N force, while a friction force pushes the car towards the south. Starting from rest, the truck pulls the car 60 meters toward the north in 25 seconds.

    What is the magnitude of the friction force acting on the car.

    2. I'm not sure what equations I should use, I'm really bad at physics, (this is my first year, and it's phy h).

    3. I have already drawn my free body diagram. Should I include the car and truck as one object, or tow seperate. -

    a = ???
    vo= 0
    t= 25
    x= 60

    x=vot + 0.5at^2

    Help please
  2. jcsd
  3. Sep 24, 2010 #2


    User Avatar

    The diagram isn't a big neccesity here but it will help. The more detailed it better.
    Questions 4 u:

    Is the tow trucks mass and friction relevant? ( This will answer your second question)

    a=? ( you have the right formula) but what acceleration is it in this case?

    And most importantly what acceleration would there be if no friction?
  4. Sep 25, 2010 #3
    Thanks, I got it. I understand.

    Thank you.
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