Can A Cannonball Float?
Of course a cannonball can float. But there’s a catch. The catch is that it depends on the density of the liquid or fluid you are putting the cannonball in. If the object is less dense than the liquid you are putting in, it will float. In fact, there is a planet that is less dense than water. Saturn. If you had a large enough ocean, Saturn would actually float in it.
But what liquid is dense enough (at room temperature) to allow a cannonball float?
Strange as it sounds, a cannonball will float in liquid mercury because the mercury is more dense than the cannonball.
Watch:
https://www.youtube.com/watch?v=Rm5D47nG9k4
Reference:
http://zidbits.com/2010/11/can-a-cannonball-float/
#science #experiment #chemistry #mercury
Im glad he is wearing gloves.... But arent the fumes dangerous?
ReplyDeletemad as a hatter
ReplyDeleteI remember when I was a kid, somebody brought a bottle of mercury into our class and we all got a little poured into our hands to play with. Ahhh, the "good" old days.
ReplyDeleteI used to work for a physicist named Brian Jones, who runs http://www.lsop.colostate.edu/ and we designed and fabricated physics demos for kids. At one point he asked "do bowling balls float?" and we're all "... no?" So he says "okay calculate the density." Sure enough, any bowling ball under about 5kg floats. He's all "I want to make a raft with forty lightweight bowling balls and put it in a pool and put a kid on it." So, where do you get 40 bowling balls? The cost, new, was higher than the whole Little Shop Of Physics yearly operating budget. Then, there was the 1997 Spring Creek flood, which sucked because it killed a bunch of people, but it also flooded the school's student center, and more importantly, the bowling alley in the basement, which was entirely destroyed. We went over and asked if we could have their bowling balls. But... there weren't any lightweight ones. They'd all floated away. So much for that plan.
ReplyDeleteMy old chemistry teacher demonstrated this to us but with some screws and bolts in a small beaker with mercury. She also told the story of her early days as a teacher when she demonstrated that while most metals objects float in mercury her new wedding ring made of gold would sink to the bottom but didn't realize that mercury amalgamates with gold and the ring started withering away even after she fished it out of the mercury. Apparently she managed to get it to a jeweler that could save it but it was a bit smaller afterwards.
ReplyDeleteIt's not just gold, Anders Öhlund: mercury aggressively amalgamates with a ton of metals. Sodium amalgam is vile stuff, and a drop of mercury will eat through aluminum faster than concentrated acid would. There are some amazing youtube videos of that. Also does some interesting things if you put a drop on an older all-copper penny.
ReplyDeleteThat tub of mercury could poisen a small town.
ReplyDeleteEric Ramos: if we assume that pool is a meter wide, two meters long, and half a meter deep, it's about 13,000 kg of mercury. We currently release about 2,000,000 kg of mercury into the atmosphere every year, of which about 70% is from coal-fired power plant emissions.
ReplyDeleteJohn Bump You're not wrong, but the atmosphere is also huge. And most people don't live down wind of a coal plant (i'm not trying to defend the practice).
ReplyDeleteWhere as the US EPA safe exposure level for mercury in water is 0.002 mg/L.
Mostly for me it's 'why the heck do you need a TANK of quicksilver!'.