WHY does density determine whether an object floats or sinks in terms of Archimedes Principle?

Question

EXPLAIN IN TERMS OF ARCHIMEDES PRINCIPLE

Answer 1

Archimede's Principle says that objects float if they displace water equal to their weight. The density of the object doesn't really matter, unless what you mean is that objects that float (logs, battleships, or whatever) have average density of less than water.

Answer 2

Well, think about it. Throw a rock into a pond and it sinks. Throw a stryfoam ball into the pond and it floats. What's the difference between the two object? They have a different density. Archimedes principle is just a quantification of that.

Answer 3

When an object is placed in a fluid, there are two forces acting on it. One is the force of gravity, which is equal to it's weight. The other force is the force of buoyancy, which is the force of the fluid on the object and is equal to the weight of the fluid displaced. If the density of the object is greater than the density of the fluid, then the force of gravity on the object is greater than the force of graviety (weight) of the fluid displaced, so it the object is pulled to the bottom or sinks. If the density of the object is less than the density of the fluid, it will displace fluid until the weight of the fluid displaced is equal to the weight of the object, at which point the object has gravity and the buoyancy acting on it equally and it is in a state called equilibrium. The forces on it being equal, it does not rise or sink and therefore floats on the surface.

Answer 4

The amount of bouyant force that a liquid (say water) can apply on an object is proportional to the volume of the liquid displaced by the object. If a 5 lb object is going to float, it needs to displace enough liquid such that the bouyant force is 5 lbs.

Now, if you had something with a very very high density, it could be incredibly heavy but incredibly small, so it would only displace a small amount of liquid. If it only displaces a small amount, the bouyant force will be low and it'll sink.

If you had some with a very very low desnity, it would be incredibly light, and even if it was a very small object, the bouyant force could be large enough to support it.

Answer 5

Archimedes' principle states that the buoyant force on an object is identical to the weight of the fluid it displaces.

Water has a density of about 1000 kilograms per cubic meter. That means 1 cubic meter of water weighs 9810 Newtons.

So, if you fully submerge an object with 1 cubic meter of volume, the buoyant force on the object will be 9810 Newtons. If the object weighs more than 9810 Newtons, then gravity overpowers the buoyant force, and the object sinks. If the object weighs less than 9810 Newtons, the buoyant force overpowers gravity, and the object floats to the surface, until part of it sticks out of the water (meaning it no longer displaces 1 cubic meter).

Saying than a 1-cubic-meter object weighs more than 9810 Newtons is equivalent to saying the object's density is greater than that of water, since
W / V ~ rho
where W = weight, V = volume, rho = density, and ~ means "is proportional to".

Likewise, saying a 1-cubic-meter object weighs less than 9810 Newtons is equivalent to saying the object's density is less than that of water.

Answer 6

Eureka !, a substance having a lower Density than water will float as it exerts less downward force (displacement), than that of the upward force of the water.

Answer 7

It's physics