## Springs and Losing Energy

If you have problems installing or running Algodoo, have found a bug or need in-game help - this is it!

### Springs and Losing Energy

I'm new to Algodoo.

I'm trying to demo a horizontal mass spring system for SHM, but no matter what I do, the system continues to lose energy. [Edit 2: Solved this too. It was air resistance. Toggled that off, and I'm good now. Thanks, I think ]

Here's the design.
1. Infinite vertical plane and horizontal plane
2. Box dropped onto the horizontal plane
3. Spring connecting box to vertical plane.

I've set spring damping to 0 and friction to 0 for the box and the horizontal plane. I've also set restitution to 1 for the box and the horizontal plane.

But, when I graph KE of the box, the graph over time shows a loss of energy. What do I need to change?

Also, can I graph the sum of the spring potential energy plus the KE of the box on a graph? If so, how? [Edit: Nevermind, figured out how to group the items. Still don't understand why I'm losing energy. Air resistance?]

Thanks.
mrchinphysics

Posts: 1
Joined: Sat Mar 28, 2015 4:38 pm

### Re: Springs and Losing Energy

Dream of Algodoo as game development engine...

Kilinich
[Best bug reporter 2010]

Posts: 2098
Joined: Mon Aug 31, 2009 8:27 pm
Location: South Russia

### Re: Springs and Losing Energy

I am facing the same problem with bouncing bodies.
Simple bodies bouncing in a square room don't loose energy but when adding bearings or hinges we see a loss of energy.
There is no air resistance, all materials are set to friction = 0 and restitution = 1

Is this due to limitations of calculation accuracy?
groenkees

Posts: 1
Joined: Wed Jan 30, 2019 8:17 pm

### Re: Springs and Losing Energy

It has mostly to do with the fact that hinges don't "fixate" an object, instead acting like an elastic pivot, and that elasticity is not 100% energy conserving.
FRA32

Posts: 218
Joined: Wed Dec 03, 2014 9:51 pm