Slow Motion Flipping Cat Physics Smarter Every Day 58
Hey it's me Destin Welcome back to SmarterEveryDay So you've probably observed that cats almost always land on their feet Today's question is why. Like most simple questions there's a very complex answer
For instance let me reword this question How does a cat go from feet up To feet down In a falling reference frame without violating the conservation of angular momentum Now I've studied free falling bodies, my own in fact in several different environments and once i get my angular rotation started in one direction, I can't stop it. Today, we're going to use a high speed camera we're not going to use Alley
because this is my daughter's cat, i don't want to hurt it we're going to use a stunt cat let me introduce you to GiGi the stunt cat (music) I'll just flip the uh, the tutorial vertical and then motion track the cat it's just going to take a lot more effort in post
We're going to try to do it in a way that doesn't make anybody mad That's pretty hard to do. You gotta drop the cat Ready GiGié Good kitty Checking out the high speed data there GiGié Ok the first thing a cat does when it's falling is try to figure out which way is up.
It does this either with the gyro in the ear or with its eyes Ready to talk cat physicsé Alright. So check out this footage i captured with the Phantom Miro While GiGi goes to get a drink of water. So here's what's interesting about this to me. You'll notice that at the beginning of the drop the cat is not rotating
halfway through the drop the cat is rotating and at the very end GiGi somehow stopped rotating Newton's law says an object at rest will stay at rest unless acted on by an external force I see no external forces on this cat So what's happening hereé It's not making sense to me O.K. so in order to really get the right data
Fast Swimming Techniques Freestyle Flip Turn The Flip
On the flip turn itself, we usually see three different problems. The first problem is it. The swimmer doesn't tuck the knees and the legs tight enough to the chest, so they make a big ball. And the big ball takes too long to get over the top. If you can make you ball tight, you're gonna get your legs over much faster. The second problem we see is it. Swimmers tend to try to rotate as they're turning, so their feet will go angled one way or the other. When they really want to get them to the wall as fast as possible,
the fastest way to do that is to keep the feet square and have the toes pointed straight up, when they hit the wall, going straight over the top. The way we practice those is, we do that with an underwater drill. We put a weight belt on. We put ankle weights around the ankles. And we have them actually do the entire turn underwater. Why would we do thaté First of all, it makes him appreciate the drag factors.
When their feet or their legs are out, wide, it takes forever to get them around. When they tuck them up tight, they feel how much faster than they can get them over. It also makes him appreciate how much core strength it takes to get those legs over the top and into the wall. And if they lift their head up, they also, underwater, realize it takes more strength than if they keep their head down. The third problem we encounter is it. When the person flips their turn and they pull back with arms under water, they continue pulling until their arms are in this position. Now their feet are on the wall and they're in this position, what're they gonna doé
They're either gonna wait and get into a streamlined position, or they're going to push off the wall and get into that position as they're moving. And either way they lose. So what would we do (is), we teach that by having them pull back with that straight arm, not bending the elbow, holding the hands close together, as far away from their head as possible, and have them freeze when they hit the wall. If their arms are in that position, then they're good. If they're here, they're not.
So from this point, once they hit the wall, it's very easy to get into a very streamlined position very quickly. That will save them 0.1 ~ 0.2 (seconds) on every turn.