Why does a nail sink, but a boat float?

Question

Why does a nail sink, but a boat float?

Answer 1

Specific gravity;-} nail is solid, boat is hollow.

Answer 2

Something floats if it weighs less than the amount of water it displaces weighs. Fill the boat with metal so there are no air spaces and it will sink like the nail.

Answer 3

The key to floating is that the object must displace an amount of water which is equal to its own weight. The nail is oddly shaped and sinks. It also doesn't displace any water.

Answer 4

Because of the air in the hull.

The air makes it buoyant.

Answer 5

Easy....a boat is wider and since the water surface is wide and deep the boat floats. a nail is skinny and not wide so it sinks. its called density.

Answer 6

displacement, and surface area compared to weight,    and thanks!,  this answer takes me to level 4!!  yay!

Answer 7

a nail has no buoyancy but a huge boat has a lot of buoyancy

Answer 8

nails sink because it is heavier then boats

Answer 9

displacement

Answer 10

GOOD QUESTION

Answer 11

Boat float because of displacement.

In fluid mechanics, displacement occurs when an object is immersed in a fluid, pushing it out of the way and taking its place, so that it can be weighed.

An object that sinks also displaces an amount of fluid equal to the object's volume. Thus buoyancy is expressed by Archimedes' Principle which states that when this happens, the weight of the object is reduced by its volume times the density of the fluid. If the weight of the object is less than this quantity, it will float, if more it will sink. The amount of fluid displaced is directly related (via Archimedes' Principle) to its weight.

Displacement is used as a measure of the weight of ships (see: Hull (watercraft), load line and Stability conditions (watercraft). The displacement of a vessel is equal to the weight of water it displaces when afloat.)

Vessels such as naval ships and icebreakers are often measured by their displacements. The unit of measure can be long tons or metric tons depending on the country of origin. The ship can be measured in light condition, fully loaded, or normal (usually fully loaded, but with about two-thirds of fuel and unconsumables). For official purposes, the Washington Naval Treaty introduced the standard displacement, which was the displacement fully loaded but with no fuel or reserve feed water.

Answer 12

It's all about density!

A boat, being made of wood, is lighter and therefore less dense, causing it to float upon water.

A nail, being made of pure metal, is heavier and therefore more dense, causing it to sink straight to the bottom.

If you want to go even deeper, I believe it also has something to do w/ the atomic makeup of both substances (the former being less populated in the ionic constitution of each atom, and the latter being far more so).  But, lets leave all that to the professional metaphysicists!

Hope this helps!

Answer 13

Wow, someone's been thinking. I remember asking my physics teacher that same question...

It has a whole lot to do with the amount of water that's displaced by each item, and even more with the surface area that makes contact with the water.

Try this, take a piece of wood about 1foot square, and place it in a bucket of water...observe what happens.take it out.

Take a nail, and place it in the same bucket of water....observe what happens.take it out.

Take a piece of paper and cut it about 1 foot square, and place it in the same bucket of water. observe what happens...take it out.

now, check this out...and I won't go into detail, but just tease your brain...if you were to place the nail on top of the piece of wood, would it sink or float?

You see, the more surface area that's in contact with a body of water, the more likely an item is to float...but of course that's not the only factor at work...check out the other factors at the following site

http://science.howstuffworks.com/questio...

Answer 14

It doesn't have to do with weight but density. The nail has a density above 1.0grams per milliliter which means it will sink. The boats density is below 1.0grams per milliliter so it will float.

Answer 15

Because a nail has no bouyancy.

Answer 16

Buoyancy.  People also have to believe that it will float or it will actually sink. ;-)

Answer 17

because the weight of the boat is dispersed evenly over the water which keeps it from sinking.  a nail is not constructed the same way.

Answer 18

Because nails are denser than water, boats are made of material that is less dense.

Answer 19

Why does a nail sit on the ground, but a plane fly?

Answer 20

buoyancy

Answer 21

A boat is designed to displace the same amount of water equal to its weight. This makes it buoyant and therefore floats.

Answer 22

because God made all men equal

Answer 23

They are both made of metal (newer boats).  But boats are like half balloons (mostly air inside).  If the boat was crush into one large ball (with no air pockets), it will sink just like a nail.

Think of it this way, a balloon full of air is mostly air.  So it is "lighter" (or more buoyant).  And the same goes for a boat.  But that is the same reason why boats SINK when rammed and let the water in.

Good question.

And Good Luck.

Answer 24

It's not the density of the material, but it's relationship to the water it displaces.

A ship made of the same steel that the nail is made up will float because it displaces more mass of water than the mass of the steel in the boat.

the nail, due to its shape, doesn't displace more mass of water than the nail weighs.  If you were to reshape the nail into a shell shape- it too would float.

Answer 25

due to density of things  ie realation of weigh and surface of things

Answer 26

density wood has air pocketes a nail is just solid

Answer 27

Displacement of water versus the displacement of air (which is lighter than water). The more dense an object the more area of air will be required.  Take aluminum foil.  If you ball it up very, very tightly- it sinks.  Now if you take the same amount of foil and hollow it out to look like a bowl- it floats.

Answer 28

buoyancy and a boat has more surface space, so it displaces more  water.....