# Comservation of Energy

1. Feb 26, 2009

### junior78

1. The problem statement, all variables and given/known data
A lady finds herself in a very odd contraption.She sits in a reclining in front a large,compressed spring.The spring is compressed 5.00 m from its equilibrium, and a glass sits 19.8 m from her outstretched foot.
a)What was the k value ?
b) What is the coefficient of friction?
c)The principle of conservation of energy states that energy is neither created nor destroyed. Which of the following describes the transformation of energy in this problem?
---Conservation of energy does not apply to problems involving nonconservative forces. Thus, the potential energy slowly disappears during Albertine's trip
--The potential energy was turned into Albertine's kinetic energy, which was then converted into internal (thermal) energy
--The potential energy was turned into Albertine's kinetic energy, which is now stored in the floor as frictional potential energy
--The potential energy was turned into elastic frictional energy, creating the frictional force
2. Relevant equations

3. The attempt at a solution

Using an applet I found k to be 95N/m
Using potential energy and Work done I found uk to be 0.102
My question regarding part c because i believe is the first one but I wanted to consult to be for sure

Thanks

2. Feb 26, 2009

### LowlyPion

It seems part of the question is missing, but as to what you are asking about part C, how is the potential energy disappearing?

When you rub your hands vigorously on a carpet, what is your sensation? Are your hands still the same temperature? Is the carpet?

Did the energy of your activity disappear altogether?

3. Feb 26, 2009

### junior78

The question was your input on which one would think out of the four statemenst justify the querstion in part C
The principle of conservation of energy states that energy is neither created nor destroyed. Which of the following describes the transformation of energy in this problem?
And the statements with "---" are the options
"Accroding to your example I would say that the energy never dissapears on neither one..

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook