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Homework Help: Conservation of Energy, Velocity, Ramp, Angle

  1. Apr 21, 2012 #1


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    1. The problem statement, all variables and given/known data
    This isn't really coursework or homework, but something I really want to confirm.

    There is a ramp of height h on an angle θ that a car is placed on that leads to a wall perpendicular to the ground (looks like this: |∠). When calculating velocity of the car when it hits the wall using E = E', do I need to account for θ?

    Every instinct I have says yes, but I want confirmation.

    2. Relevant equations
    E = E'

    3. The attempt at a solution
    E = E'
    mgh = 1/2 mv^2

    Solve for v .. doesn't really matter what it is.

    Is the velocity of the car in a momentum equation (p = mv) equal to v or is it equal to v*cosθ?
  2. jcsd
  3. Apr 22, 2012 #2
    You have to take the angle the acceleration parallel to the ramp is a = v'(t)= g sin(theta)

    Integrate it to get the result.
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