Work and Energy on a curved track with friction

AI Thread Summary
The discussion focuses on calculating the kinetic energy at position B and the work done by friction from position A to position B for a marble moving along a curved track. It is noted that energy conservation applies from point B to point C due to the absence of non-conservative forces. However, the presence of friction complicates the calculations between points A and B, leading to two unknowns: kinetic energy at B and the work done by friction. Participants emphasize the importance of the Work-Energy Theorem, highlighting that friction performs negative work, which must be accounted for in the energy equations. The need for additional information about friction, such as the coefficient, is also raised to facilitate a complete solution.
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Homework Statement


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.

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!
 
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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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