I've been wondering this for a little while now.
Does the pressure of the water bring it up?
Or something else?
2007-10-28 09:27:58 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Pressure is one way to look at it. Consider a floating object in equilibrium. Say a toy boat, mass m. It has a weight, m*g, a gravitational attraction to the center of the earth. But so does the water. At the bottom of the boat's hull there is water pressure. That's the water molecules bumping into each other, the sides of your bathtub and the hull of the boat. This pressure presses in a perpendicular way against any surface it comes up against. If the pressure is high enough and the object's weight is little enough, the object floats.
Everyone else has been giving the density explanation. Pressure under the surface comes from the density of the water and the depth of the point you're interested in.
Another way to think about it: When you place the boat in the water, it pushes some water out of the way. The water pushes back because of the weight of the water above it. If the boat is lighter than the weight of the water the boat pushed out of the way (the weight of the volume displaced), the boat floats.
2007-10-28 10:35:24 · answer #1 · answered by sojsail 7 · 0⤊ 0⤋
Anything with a density less than water (less than 1 g/cm^3) will float in water.
I think what happens is that the water falls underneath the object and that happens until it's floating on top.
2007-10-28 16:34:29 · answer #2 · answered by hcbiochem 7 · 0⤊ 0⤋
It is all about the density - if the object dropped in the water is less than that of the water it will float.
2007-10-28 16:35:59 · answer #3 · answered by bravokardia 4 · 0⤊ 0⤋
It is something else. Things float in any liquid because their mass is less than the liquid.
2007-10-28 16:34:13 · answer #4 · answered by dude 7 · 0⤊ 1⤋