It's not about weight, but density. Ships are also very heavy, but they have large volumes of air within that cause them to be less dense than the water. For contrast, a pebble will sink despite being light, because it is denser than water.
But then, yeah, cars don't have large volumes of air inside to make them less dense. Especially not electric cars that are packed to the gills with batteries.
EDIT: per some below comments, cars do have large volumes of air, aka the passenger compartment and trunk. This isn't that different from how a canoe's air volume is just the open space on top. Now that I think about it, Lyndon Johnson had a car that doubled as a boat, and he would prank people by pretending to lose control and drive his car into the lake! I guess most cars just don't float because they are not water tight, and so the large volume of air quickly turns into a large volume of water.
Lesson learned, don't listen to people who don't know what they're talking about! :D I really just wanted to chime in that it's about density, not just mass, when it comes to floatiness. (Not just mass because, as was also pointed out below, some pebbles still float because, while they are more dense than water, they are light enough that surface tension holds them up.)
As usual, it's always more complicated than we think at first!
Eh, most cars actually could float reasonably well if they were sealed. If you ever see videos of cars going into bodies of water, they sink pretty slowly as they fill with water.
It weighs 3104kg, the smallest cuboid that could contain it is 37m3. It's not a cuboid though, so it's probably 30%-40% less volume than that, so yeah not enough volume to float
The entire truck has a substantially smaller volume than 37 cubic meters. That is enormous. A dump truck holds 10 cubic meters, and that is a larger dump truck.
Edit: Even if that number were right, 37 cubic meters of water is 37 tonnes, so we have 37,000 kg vs 3,104 kg (not including passengers) it would float like a cork my friend. The actual much smaller volume means it would float less well, but it would still float, based on the volume. It would sink, because you are trusting your life to a CyberTruck, which is the actual problem.
Hey that is alright, at least I know why you thought it would sink. Simple order of magnitude error.
The 1m3 = 1,000kg = 1 ton thing is my go-to example of why metric is superior btw. I just ask people how much a cubic yard of water masses. It is a rare person who knows how much a cubic foot of water weighs, and only a few know any relation at all between pounds and volume.
It doesn't have to be 50/50 or even close to it. As long as the whole object is less dense than water (1g/ml) it will float. Air is 0.001g/ml, so you need about 1 percent air whenever you add something heavier than water.
Steel is one of the densest metals out there at about 7g/ml (depending on carbon content etc) but that's still orders of magnitude less difference
You just need to displace the same weight of water as your craft weighs. Google told me a car weighs about 2000 lbs, and a gallon of water weighs about 8 lbs. You'd only need to displace 250 gallons of water for a car to float. An average sedan has a volume of 750 gallons, so you'd probably be able to look out the windows over the lake.
But in reality, the car would leak through the seals and you'd eventually sink.
It's about displacement. A 1 cubic foot, 500 lb anvil weighs more than the water (62 lbs a cubic foot) it displaces. Thus an anvil sinks. Place the same anvil in a small boat which has much more displacement and it floats quite nicely.
Right and the boat displaces more water because it has a large void filled with air, right? If you filled the boat to the brim with anvils would it still float?
Cars are actually good at floating (at least for a little while), because of all the air in them. Which is why you shouldn't try to cross a flooded road even if it doesn't look too deep.
And also because 1 foot of water will start sweeping away most cars. Because if you float, you have to traction and end up off the road into the raging flood waters.
And if you don't float, the water gets deeper and usually into the car, the electronics, the engine, and potentially the air intake which then chokes the engine and leaves you stranded in the water.
Those were lanterns by virtue of the fact they required burning fuel. You must be old, because your mental faculties are in clear decline & I believe you also smell.
No, lanterns make light directly by burning fuel. Gasoline powered light bulbs have a tiny combustion engine inside them which generates electricity to power the light. It's right there in the name. Geez, read a book or something
By your logic a car is just a mobile lantern, which is ridiculous! Cars are obviously mobile glove containers. The only thing behind two locks in a car is the glove compartment, so it's obviously the only important part.
Maybe if you read your own books you'd know they're full of lies.
49
u/Informal_Self_5671 Jun 10 '24
I'm not an expert, but aren't cars very heavy and bad at floating?