Falling Dollies?!

I have always been a pretty easily entertained person. When I was little, one of my favorite toys was probably one of those Russian dolls that comes back up when you push it over. It wasn't until recently that I discovered the underlying physics in it. There are two concepts that can be applied here: a stable equilibrium and (somewhat) oscillating motion.



There's my doll thingy. It's equilibrium is when it's standing straight up. I removed it from equilibrium by pushing it over. When I let go, it didn't travel away from equilibrium, but towards it. It took a little while, but it eventually ended up standing again. This demonstrates a stable equilibrium.

It shows oscillating motion because it goes back and forth. And if you were to graph it, it would look like a cosine graph. Haha.

There is more weight in the butt of the doll, which is what makes it go back to equilibrium. The center of mass/gravity is closer to the ground. Also in the butt end of the doll is a bell. I honestly don't know how my parents dealt with that thing. I could barely stand it long enough to take decent pictures. (Speaking of pictures, sorry they're not very nice. My photography skills are in short supply this weekend.)