yo-yo
dr. dolittle | September 16, 2016 Image from Wikimedia commons https://commons.wikimedia.org/w/index.php?curid=1475156
Until now I had assumed that a "peep" was that squishy sugar-covered marshmallow treat that we enjoyed as kids and a "yo-yo" was a toy on a string. As it turns out, peep and yo-yo are also term used to described types of diving patterns. A square dive is one in which there are no excursions to the surface, known as a "peep", except at the end of the dive, of course. This is in contrast to a yo-yo dive in which divers repeatedly "peep" for a moment at the surface during a dive. The problem is that yo-yo…
rallain | January 27, 2010This is actually been sitting around for a while waiting for me to post it. Here is another short Christmas-toy demo. I am going to pull this yo-yo at different angles and on two different surfaces. Check it out.
What is going on here? Let me look at the first case where I pull the yo-yo and it slides without rolling. Here is a diagram.
Normally, I would just say - "hey - a free body diagram". And this is one, but you have to be careful. Normally, a free body diagram treats an object as though it were a point mass. You can't do that in this case because you have to consider rotation…