Solving work energy problems, with velocity and friction as givens.

AI Thread Summary
To solve a work-energy problem involving initial and final velocities along with friction, the equation KE1 + GPE1 - Friction = KE2 is a good starting point. The key challenge is finding the height, which requires understanding how to express kinetic energy (KE) and gravitational potential energy (GPE) in terms of the variables provided. If the mass is unknown, it can be represented as a variable, allowing for cancellation in the equations if friction is proportional to mass. Creating a hypothetical problem with different values can also aid in understanding the process. Ultimately, the goal is to isolate the height variable within the context of the energy equation.
nickyak
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I need to solve a work energy equation for height that has initial velocity, final velocity, and work done by friction as the only givens, I don't want to give the full problem, but I can't even find how to do that in my physics book so any help would be appreciated. right now I have KE1+GPE1-Friction=KE2
 
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nickyak said:
I don't want to give the full problem
You will at least need to disclose what it is that you are asked to find.
 
He needs to find the height. Can you make up a problem based on the given one? (Change all the numbers and wording)
 
PhizKid said:
He needs to find the height.
Hmm.. yes, missed that.:blushing:
Ok, so you have an equation regarding energy, and presumably you can write down expressions for KE etc. if only you knew the mass. Is that the problem? If so, just put in an unknown for mass and hope it cancels. (If the friction is proportional to the mass then it will.)
 
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