Algodoo

1. Please define m, g, and k in the Lspring formula.

2. I found that increasing the Simulation Speed to about 1.75 or 2.0 in both my scene and in yours, makes the scenes a bit more interesting to watch because then I didn't have to wait so long for things to happen and for behaviors to change.

3. In Steve Mould's video he states: "If you get this mass just right and the length of this string just right something weird happens." I'm not certain but I think he actually meant to say: "If you get this mass just right and the length of this spring just right something weird happens." In the first iteration of my scene I did not use a string between the spring and the weight, but I wanted to replicate his scene as accurately as possible in Algodoo and so I put it back in. After experimenting with and without a string ("rope" in Algodoo), it made no difference in the behavior of the spring/weight oscillator (as long as the spring doesn't reach its compressed limit, allowing the rope to go slack for a brief instant).

4. I wasn't able to find anything on the Web that explains WHY a spring/weight combo behaves in the manner described. I think it might have something to do with Chaos Theory, but not sure. Any ideas?

Q: Please define m, g, and k in the Lspring formula.
A: m = mass, g = gravitational constant, k = spring constant, Lspring = spring target (free) length.

Q: Increasing the Simulation Speed to about 1.75 or 2.0 makes the scenes a bit more interesting.
A: We might be able to increase the frequency by reducing the mass and adjusting the spring length accordingly.

Q: A string ("rope" in Algodoo), makes no difference in the behavior of the spring/weight oscillator.
A: I agree. IRL a string is easier to use. In Algodoo it's easier to just change the spring length.

Q: WHY does the spring/weight combo behave in the manner described?
A: If you search on "elastic pendulum" you will find a number of sources that describe the math behind the general behavior. Info on "resonant elastic pendulum" is harder to find. I looked thru many sources looking for a simple equation like the one in my scene but couldn't find it so I ended up deriving it myself.

Quote: I looked thru many sources looking for a simple equation like the one in my scene but couldn't find it so I ended up deriving it myself.

Reply: You never cease to impress me, s_noonan.