Swimming In Syrup Is As Easy As Swimming In Water

hey everyone today we're going to be seeing if you can swim just as fast in syrup as you can in water i recently read a research article that said you can swim just as fast and syrup as you can in water because even though the syrup is more viscous you can push off of it more and so even though it's slowing you down you can push yourself through it easier and so it ends up equaling about the same speed as you can swim just in water even though it's less viscous and you can get through it easier but you can't push off it as easy so today i wanted to test that out so first let's start off with our small scale test here so to start off i'm going to be testing speeds with my turtle here with water and then with syrup and seeing how they compare okay there's two quarts [Music] okay here we go for the head-to-head race three two one syrup wins even with hitting the side let's try that again three two one it's way faster in the syrup i've taped a straw to each of their heads and then i have a string going down the center and so this will at least keep them from going too far off course so they can at least finish the track a little three two one same time okay three two one again the same so it really is the same to swim in syrup versus water so somehow the turtle that was swimming in syrup was able to swim the same speed as the turtle that was swimming in water but what's really weird about this is if i test the viscosity of the two liquids you obviously get a higher viscosity for the syrup one way to test the viscosity of something is to drop a sphere in a cylinder of the liquid now watch what happens when i drop a sphere in a cylinder of water compared to the syrup so here's how long it takes to drop in water three two one and here's how long it takes to drop in syrup three two one [Music] [Music] so the syrup is about twice as long as the water so somehow just dropping a sphere in syrup takes longer it's harder to get through and get to the bottom than in water so why is swimming any different why doesn't it take twice as long for the turtle to swim through syrup compared to water well the reason for this discrepancy is because for human swimming and it looks like for toy turtles as well the dominant force that's keeping you back the main resistance is called form drag now in fluid mechanics form drag means that for a shape like this book and this sphere even though they have the same cross-sectional area the force on it wouldn't be the same if you're trying to drag it through a fluid for example if you hold this book in front of a fan you would feel a greater force than if you held this ball in front of a fan it's because this book isn't very aerodynamic so it creates a separation layer larger than the ball so it creates a lot more friction behind it and turbulence and that slows it down the drag is more on this book for this ball it lowers the separation area so there's less drag behind it it's more aerodynamic so in things that aren't very aerodynamic it means that the dominating factor the main resistance stopping them from moving forward through a fluid is their form the shape of them now the basis for this experiment comes from a research paper from the university of minnesota where researchers were arguing whether or not a human could swim faster if the liquid were more viscous that they were swimming in some people who were very well renowned in fluid mechanics argued that well if the fluid were thicker then it's harder to get through so of course they're going to slow down but that some people were saying well if it's thicker you can push off it harder so you should be able to go faster through it so what these researchers did is actually do an experiment to prove it what they did is they filled a swimming pool with guar gum to make it so it was twice as viscous as regular water and then they compare the times of professional swimmers compared to lay swimmers and water and then the guar gum to see if their times change between the two and what's really interesting is they found that the times didn't change at all they had hardly any variation between the two what they found was that in this range of viscosity it doesn't matter that the syrup's thicker because it gives you more things more liquid to push off of a harder more viscous liquid to push off of so it cancels out the added drag you get from being in the syrup but if you leave this viscosity range of one to two times the viscosity of water then you're not going to see the same effect for example when i first did this experiment i just did it with really thick syrup and in that case here's what happened okay let's see three two [Laughter] one not quite as fast i would say [Music] okay that was like 25 seconds so not even close to what it is in water so if the viscosity is too much the skin drag does overpower the form drag and so you can't move as fast at all the turtle could barely get through that syrup so when i got into the range of four times the viscosity of water then it was much too viscous for the turtle to swim in it i'm not sure how a human would do in that but the turtle wasn't able to go at all hey everyone thanks for watching another episode of the action lab i hope you liked it i hope you learned something if you did don't forget to hit the subscribe button and also don't forget to hit the bell so that you can be notified when i release my latest video and you can also check out the actionlab.com to see the two action lab experiment boxes that i put out and thanks for watching and i'll see you next time

Channel: The Action Lab

Views: 2,673,307

Keywords: syrup, swimming in syrup, form drag, fluid mechanics, the action lab, science, physics

Id: NdAganj2Gfo

Length: 6min 45sec (405 seconds)

Published: Tue Oct 20 2020