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# Energy changes in mass spring system watch

1. Question: List the diff types of energy change involved in the oscillations of a mass spring system. Describe the energy changes when the masses move from the lowest point to highest point.

The markscheme states that EPE decreases from the lowest point to the highest point, but surely it should decrease then increase? Shouldn't it be 0 at the mid point where extension is 0?
2. (Original post by ambershell27)
Question: List the diff types of energy change involved in the oscillations of a mass spring system. Describe the energy changes when the masses move from the lowest point to highest point.

The markscheme states that EPE decreases from the lowest point to the highest point, but surely it should decrease then increase? Shouldn't it be 0 at the mid point where extension is 0?
When the mass is at rest, the spring still has an extension (this is not where the spring is at its natural length - that would happen if the mass was removed). So it does have EPE here. When it is below the rest position, the extension is even greater, so it will have more EPE here. When it is above the rest position, the extension is smaller, so the EPE will be smaller, with the smallest value at the top of the oscillation.
3. Lowest point, maximum elastic potential, as goes up kinetic energy increases, speed is max at Equilibrium point, so the potential energy is minimum. When highest height, gravitational potential is max again but elastic potential is minimum
4. (Original post by ambershell27)
But isn't elastic potential energy 0 at the equilibrium point? How can it be minimum at greatest height if the spring is compressed?
It doesn't compress of sorts, it's returned back to what it would be if no load was attached, the Equilibrium point is still technically stretched.

Say you add a 100N weight to a spring system and leave it, it will extend yes?
Now if you pull it down past this point when it was stationary it will oscillate up and down, above and below is the previously 'stationary point' when it's not oscillating
5. (Original post by Pangol)
When the mass is at rest, the spring still has an extension (this is not where the spring is at its natural length - that would happen if the mass was removed). So it does have EPE here. When it is below the rest position, the extension is even greater, so it will have more EPE here. When it is above the rest position, the extension is smaller, so the EPE will be smaller, with the smallest value at the top of the oscillation.
Oh, that makes sense. I assumed the movement of a system without a mass so didn't consider that the spring was always extended, as opposed to switching between extension and compression. Thanks for the help!
6. The following post may help.
https://www.thestudentroom.co.uk/sho...2&postcount=13

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