Algodoo

s_noonan -- What is the premise or the point of this scene?

This scene shows how to extend the capabilities of Algodoo. Try to make a simple spring mass system in Algodoo with a 1 mm steel block with a mass of 0.00000785 kg and a 1.5 mm spring with k = 0.025 N/m.

Okay, now I get it!

FYI. I was able to make a simple spring mass system in Algodoo with a 1 mm steel block with a mass of 0.00000785 kg and a 1.5 mm spring with k = 0.025 N/m. It was not too user friendly because it's hard to select small stuff, but the simulation ran OK and gave the expected results.

Interesting. I'll play around with that.

Thanks.

After playing around with it, I can appreciate how difficult it is to accurately make and to work with a 1mm block.

That's not something that I needed to do for any of my previous scenes, and I doubt that I would ever need to do that in any future scenes. It's just too tiny for any practical purpose!

I would typically make scenes using 1" = 1 Algodoo meter without any scaling and the inertia effects and gravity forces would be all wrong. I decided to tackle metric scaling first, since most of the world is metric. I can now use Imperial units and the scene will respond realistically. One interesting thing that I found while making these scenes is that the natural frequency of a spring mass system in earth's gravity is dependent only on the spring deflection when the mass is at rest.

S: "One interesting thing that I found while making these scenes is that the natural frequency of a spring mass system in earth's gravity is dependent only on the spring deflection when the mass is at rest."

R: I haven't confirmed it, but my assumption is that the force/distance curve of Algodoo springs is linear (i.e., bound by Hooke's Law). I think they would need to be linear in order for the above statement to be true. What do you think about this?

Yes, Algodoo springs are linear. The natural frequency (in radians/sec) of a spring mass system is w=(k/m)^0.5. k=F/x and m=F/g which means w=(g/x)^0.5. That equation is similar to the pendulum equation which is w=(g/L)^0.5.

Awesome. Thanks!