# Electrical equivalent circuit

#### mathilder7

Joined Oct 30, 2018
4
I have a problem with finding the equivalent circuit to a mass-spring system and can't find the answer to it anywhere. Hopefully someone here can help me. The mass-spring systems relevant for the question are attached as links in this post.

THanks

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#### ericgibbs

Joined Jan 29, 2010
8,887
hi m7,
Welcome to AAC.
Please post your attempt so that we can guide you.
E

#### mathilder7

Joined Oct 30, 2018
4
I've found some equations for the circuits, but going from mechanical to electrical seems to be worse than i hoped for.

For circuit number 2 I've found this:
ma1 + 3k*x1 - 2k*x2 = 0
2m*a2 + 5k*x2 - 2k*x1 = 0

#### WBahn

Joined Mar 31, 2012
24,857
I've found some equations for the circuits, but going from mechanical to electrical seems to be worse than i hoped for.

For circuit number 2 I've found this:
ma1 + 3k*x1 - 2k*x2 = 0
2m*a2 + 5k*x2 - 2k*x1 = 0
Just set up the differential equations for both and match terms. Don't forget to take into account initial conditions, too.

#### mathilder7

Joined Oct 30, 2018
4
Am I on my way to something or is it completely wrong? Haven't done it before

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#### MrAl

Joined Jun 17, 2014
6,650
I have a problem with finding the equivalent circuit to a mass-spring system and can't find the answer to it anywhere. Hopefully someone here can help me. The mass-spring systems relevant for the question are attached as links in this post.

THanks
Hello there,

Unfortunately both of your drawings might be a little too ambiguous.
Are you saying that there is no damper in either one? That would be unusual but it's up to you. That means whatever happens never stops.
Also, where is the force? Alternately, what are the initial conditions?