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Homework Help: Pushing Cart Down a Ramp

  1. Sep 12, 2008 #1
    1. The problem statement, all variables and given/known data
    A professor has to haul a cart down a ramp. The ramp has an angle of about 10 degrees and is about 5 meters long. His initial speed at the top of the ramp is 6 m/s, and the cart has a mass of about 95 kg. How hard does he have to pull on the cart so that at the bottom of the ramp, its speed does not exceed 7 m/s? Neglecting friction, what is the magnitude of the minimum force he has to exert on the cart?

    Initial Velocity: 6m/s
    Final Velocity: 7m/s
    Mass: 95kg
    Distance: 5m
    Angle: 10

    2. Relevant equations

    Vf^2=Vi^2 +2ax

    3. The attempt at a solution

    Well first I found the acceleration of the cart.

    49=36 +2a(5)

    Then I thought that the net force would be
    F=mgsin10 + ma


    F= 95*9.8*sin(10) + 95*1.3 = 285 N

    But Im still getting it wrong. Did I make a mistake someplace?
  2. jcsd
  3. Sep 12, 2008 #2
    Ohh nevermind I got it. I was right, dumb mistake.
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