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Homework Help: A Coasting Car

  1. Nov 25, 2007 #1
    This is my first post and im sorry for any mispelled words or incorrect grammer

    This is a problem for my grade 10 physics class
    A car of mass m coasts down a hill inclined at an angle theta below the horizontal. The car is acted on by 3 forces. The normal force N exerted by the road, a force due to air resistance, F(air) and the force of gravity mg. Find the total work done on the car as it travels a distance d along the road.

    Any suggestions :)
  2. jcsd
  3. Nov 25, 2007 #2
    what are the forces in use? There has to be some numbers.
  4. Nov 25, 2007 #3
    Well it's asking for an equation to find the total work done on the car. There arent any numbers.
  5. Nov 25, 2007 #4
    ok then, we know that they are asking for three forces,
    a)air resistence
    B)force of gravity
    c)normal force

    so the equations in use is are derived from the sum of F(force)=ma
    that mean we just add up all the force to make a net force.
    Normal force is the force applied downward and parallel to the road
    the force of gravity is essentially weight, or the amount of force applied towards the earth's center
    and the the wind resistence is just a small force applied on the force of the car accelerating downward, which is the force of gravity applied at a certain angle.

    Does this help?
  6. Nov 25, 2007 #5
    How am I supposed to put friction into the equation?
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