how do ships float?
In: Physics
A rock will sink, because it’s more dense than water.
A balloon will float, because it’s less dense than water.
So what happens when you attach a rock to a balloon??
Assuming the balloon is much bigger than the rock –
the rock will pull the balloon down a little bit. But not much. In the end, the balloon floats, a little lower than before, with the rock underwater.
If you calculate the density of the rock and *just the part of the balloon under water*, the average density will be exactly the same as that of water (if it was more, it would sink down more, if it was less it would float up more).
A ship is made of heavy stuff that you’d think would sink. Eg, steel. But it’s also hollow, and watertight underneath. The heavy steel pulls the ship down a bit, but since the ship is mostly hollow, it’s less dense than water overall, on average.
The ship will have special equipment and procedures to make sure it stays filled with air – pumps to pump out any water that does get in, careful regular inspections to make sure there’s no danger of leaks forming, and so on. Because if it did fill with water, the average density would be more than water’s density, and the whole thing would sink.
Latest Answers