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Homework Help: Work and Energy on a curved track with friction

  1. Feb 13, 2012 #1
    1. The problem statement, all variables and given/known data
    From point A, the marble rests at the height of 0.895 m. Then, it is released up to point B which has a height of 0.665 m. From point B to point C, the marble falls in a projectile motion.
    Calculate the Kinetic Energy on position B and the work done by friction from position A to position B.

    3. The attempt at a solution
    Well, i know that energy is conserved from Point B to Point C because only conservative forces were acting on the marble. My problem is from position A to position B since i've got 2 unknowns, the KE in B and work done by friction. Since there is friction, The total energy in position A must be GREATER than the total energy in position B. PLEASE, HEEEEEEELP!
  2. jcsd
  3. Feb 14, 2012 #2
    Was there no other information given about friction, such as the coefficient of friction? If not, then the answer may need to include variables. See if your book's answer includes variables, which I am decently sure it should. If there are no answers provided, then just bare with me.

    You should already be familiar with the Work-Energy Theorem. You already know that friction does negative work as the marble moves, so all you have to do is set up the equation.
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