Which ways more a helium-filled party balloon or a grain of sand? Well, it's not too complicated on earth a typical grain of sand has a massive about 10 milligrams So it's pulled by gravity with about 0.1 million units a helium party balloon has a massive about three grams And thus is pulled with 30 millenons so the balloon weighs more simple Weight is defined as the force on an object due to gravity a helium balloon has a force on it due to gravity And that force is pointed downward The reason the balloon goes upward is because the buoyant force on it is greater than its weight buoyancy is a force that is applied to any object within a fluid equal to the gravitational force on an amount of fluid equivalent in volume to the object But in the opposite direction if the balloon displaces four liters of air the buoyant force pushing the balloon up is the same as the gravitational force applied to four liters of air which is about 50 millenutens at sea level Now there's one seemingly insignificant change we can make to our original question that changes our answer entirely what if instead of weight we asked about heaviness Which is heavier a helium filled party balloon or a grain of sand? If it's going to take up space in the dictionary heaviness might as well be used to mean something just a little bit different from weight Now of course a word being useful with some definition doesn't make it have that definition But English has a habit of making synonyms not quite perfect with nuanced differences And that's the case with heaviness and weight heaviness and weight are often defined not only in the same way But by each other in many cases they are perfect synonyms But weight is the word which sometimes is a strict physics word while heaviness is never that heaviness is about feeling it's about appearance heaviness generally refers to a parent weight what a scale would read from the object in question a helium balloon that floats up has a Negative apparent weight because of buoyancy a grain of sand is light and has much less mass But nevertheless positive apparent weight this means that a grain of sand is indeed heavier than a helium balloon Even though it doesn't weigh more it's important to realize that buoyancy applies to anything in a fluid Not just the things that float in the case of an object that floats upward What we're seeing is the buoyant force exceeding the gravitational force on the object But every object has a buoyant force the average person displaces about 85 grams of air and that creates a buoyant force of about a quarter of a pound Or the weight of an apple Everything in Earth's atmosphere has a buoyant force even if it doesn't float a Kilogram of steel and a kilogram of feathers have the same mass we define the message But even without air pockets in the feathers the kilogram of steel if a solid chunk is much more dense If it has the same mass, but it's more dense that means it must have less volume and thus less buoyancy The weights of the two kilograms are the same if they're at the same place on Earth But their heaviness is not a kilogram of steel is heavier than a kilogram of feathers Hey, what's going on guys? It's been a while. Has it did? I was in Brazil for three and a half weeks, right? And there was an upload during that time But it was a scheduled upload so it feels like it's been a long time for me I'm glad to be back with a nice edited video Although it's not you know super musical strictly speaking But I don't have a channel dedicated to physics and linguistics so I just put it here because why not? But I did make the background music and it was you know, I'm custom made for this so that's a thing But thank you so much for watching. I hope you enjoyed it and we're getting back in the swing of things now Obviously being gone for that long without any recording equipment or anything Put kind of a stopper on the YouTube channel, but we're back we're back now and I've got a lot of stuff planned for this summer and Big announcements and major content is coming so stay tuned and thanks for watching. See you next time. Bye You