So if I had a canoe floating in the water on earth it would sink lets

[cragar]

So if I had a canoe floating in the water on Earth it would sink let's say 4 inches down. Now I take that same canoe with the same mass and put it in a lake on the moon, suppose the moon had a lake . Wouldn't the canoe also sink 4 inches down on the moon . Assuming the canoe had the same mass and was in water both times. And I was wondering could their ever be a Gravitational field where it was strong enough to sink the canoe besides a black hole. Will the canoe sink the same depth in all G fields.

 

[SteamKing]

What happens when bodies float? Apply Archimedes principle here.

 

[Bloodthunder]

Continuing on from SteamKing, Archimedes' Principle is "Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object."

Note the word "weight", which is mass times gravitational field strength.

 

[cragar]

ok i understand Archimedes principle, Suppose we had a really strong G field, like on Jupiter, Isn't Jupiter G field so strong that if a can was placed on its surface that it would be crushed. I am just wondering if there is some weird extreme case where it would pull the boat in, probably not though

 

[Bloodthunder]

I don't think the gravitational field strength would matter.
Weight of boat is buoyed up by a force equal to weight of fluid displaced.
So W_boat = W_water.
Since W = mg and g is same in both cases, m_boat = m_water.
In that case, there would never be a situation where the boat would be sunk. The water level outside the boat would probably always be at the same level.

 

[Doomemperor]

The Gravitational force would not matter, because it is acting on not only your canoe-but on the water as well. Keep in mind that Buoyancy is the counter-force of gravity.

 

[russ_watters]

ok i understand Archimedes principle, Suppose we had a really strong G field, like on Jupiter, Isn't Jupiter G field so strong that if a can was placed on its surface that it would be crushed. I am just wondering if there is some weird extreme case where it would pull the boat in, probably not though

No, you missed what Archimedes principle says here: The weight of the canoe increases at exactly the same proportion as the weight of the water increases, so the canoe floats at exactly the same height/depth everywhere.

 

[Naty1]

You can verify Watters post via a simple thought experiment:use the equivalence principle: accelerate a body of water with a canoe floating on top...F = Ma applies to all and the float level remains the same...

 

[cragar]

ok i get it, thanks for your posts