This Weird Shape Rolls Uphill Instead of Down

hey everybody today i'm going to be showing you some things that fall up instead of down so i have a ramp set up here you can see that this end is definitely higher than this end to prove that the table's not slanted you can see my level here is flat but then put it on here and the bubble's up here so you can see this is definitely slanted you can also tell it's slanted if i set a cylinder on it it'll roll off the end but then something weird happens when i put this on it it doesn't go down in fact if i start it at the bottom of the hill it rolls up now this is really weird watch this what in the world so watch both of these at the same time now they go opposite directions what in the world what if we switch them [Music] then they contain each other we can even make it a little bit steeper here still goes up so weird again both of them on it then if i even make it a little bit steeper set it on here it should roll down right but it just stays right in place now whereas this one just goes right off really fast finally if i get it steep enough i can get it to roll down now this isn't the only phenomenon that i've seen where things can roll uphill for example check out this previous video i did with the styrofoam disc you can see that it's an easily a curved surface propped up on these books here [Music] but when i try to roll it down it rolls up how is this happening how can something roll up hill or basically fall up well what about things that we know naturally just move upward like a balloon for example well the reason that a balloon goes upwards isn't necessarily that it's falling upward but it's being pushed upward in fact gravity is still pulling things downward in fact it's pulling the air around it downward it's pulling the balloon downward but the air is being pulled a little bit harder than the balloon and so the air goes below it and pushes the balloon upward so that means if we were to take the air out of the situation for example put a helium balloon in a vacuum chamber then the helium balloon would just fall like normal and as you can see here that's exactly what happens so when i turn on my vacuum chamber the balloons will expand and what i'm going to try to do and hope for is that they'll expand but the balloon will keep it pressurized enough so that the outside air will be less dense than the helium inside of it and at that point the helium balloon should fall we're gonna fall i'm trying to turn it off right before they pop oh that one fell let's see stop floating [Applause] [Music] and oh they both fell look at that so even things that we know move upward are only moving upward because things around are moving downward faster than it is and so it pauses causes it to be pushed upward so how did i just show you two things that seem to move upward instead of downward well it's because they are actually moving downward still not up so in order for something to fall that means that its center of mass or its center of gravity if you could locate the midpoint of the weight of the object that's its center of mass or center of gravity that always is going to move downward as soon as you release an object for example a cool way to find the center of mass of an object that has a smooth stick on it like this you just move your fingers towards the center and they'll eventually find the center themselves to an exact balancing point so you'll notice on this mop here that the center point or the center of gravity is not exactly in the middle this side is longer than this side but because this side has more weight on it the center of gravity is pushed this way so the center of gravity isn't always at the same point as the center of the object so in the case of this cone shape here the center of mass is directly in the center now let's watch where the center of mass goes when i release it and it rolls uphill you'll notice that the center of mass is right here to start with and then i release it and it actually ends up lower than it was when it started so the cone didn't actually fall up it still fell down in order to fall down it had to roll but that rolling made it lower at center of gravity and so it was still falling and the same thing with the styrofoam disc that i showed the styrofoam disc just had a weight on one side of it and that caused the center of mass to be lopsided and so the center of mass actually ends up lower when it rolls up the books and thanks for watching another episode of the action lab i hope you enjoyed it if you have any questions or comments let me know in the comments section and i'll try to get to them and if you haven't checked out the actionlab.com you can check it out and see the action lab experiment boxes and see the experiment book that's for sale there as well and thanks for watching and i'll see you next time [Music] [Music] you

Channel: The Action Lab

Views: 2,037,880

Rating: 4.8567696 out of 5

Keywords: rolling uphill, gravity hill, gravity, shapes, the action lab, action lab, center of mass

Id: o4xTbyfQgps

Length: 6min 21sec (381 seconds)

Published: Wed Jan 13 2021