why a small pin sinks in water but a huge ship doesnt?

Question

prove it using Archemedes law.

Answer 1

Properly built ships displace a greater mass of water than they have themselves. This is why they float -- buoyancy. Although you may be asking a trick question: A small pin can actually be made to "float" on top of water under high surface tension. Try it: fill a glass to the brim, then keep adding drops of water until it bulges up. If you place it down VERY carefully, you can actually make a pin "float" on top of the water. This demonstrates a totally different principle than buoyancy, though.

Answer 2

WHY A BOAT OR A HUGE SHIP FLOATS???
f you fill your bathtub with water, what happens when you get in? The water rises, right? (And sometimes goes over the side.) That is because you "displaced" some of the water with your body and it had to go somewhere. The key to floating is that the object must displace an amount of water which is equal to its own weight.
The principle of floating is pretty easy, however, if you want to remain inside the boat and actually get where you want to go, your boat must have "stability" as well as being able to float. Stability means that it is designed not to tip over easily. That doesn't mean it won't ever tip over.
On a large ship like an ocean liner or tanker, the movement of one person doesn't affect the stability of the ship because it was designed to safely carry lots of weight. But on a small boat, like a fishing boat, your weight and the weight of your gear (and where you put it) has an effect on the stability of the boat.

WHY A PIN SINKS???
Surface tension allows water striders to 'skate' across the top of a pond. You can experiment with surface tension. Try floating a pin or a paperclip on the top if a glass of water. A metal pin or paper clip is heavier than water, but because of the surface tension the water is able to hold up the metal

Answer 3

Some of the above answers are good, but I think you are asking for an answer that is more clear. Here it is in two sentences:

Anything (on water) will sink until it has pushed enough water out of the way to equal the weight of the object itself. Once it pushes the weight of itself (in water) out of the way, it is either floating or sinking- depending on how much water it had to move out of the way to equal its weight.

That's what the other guy meant by buoyancy.

Answer 4

Because a small pin doesn't hold vast quantities of air? It's the same reason a leaf floats on the water until you get it wet on top, then there's no air to give it buoyancy and it sinks.

Answer 5

Archimedes' principle - a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid.

buoyancy = ρV g
ρ = density of fluid
V = volume of object
g = acceleration of gravity

Pin = small volume of displacement
Ship = large volume of displacement

Answer 6

This is a good place and time for me to show how little I know about ships. But I would think that, the ship has built in air spaces and the pin doesn't.
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Answer 7

That's why they don't build ships that look like pins. Dahh!