Archimedes' Principle
The relationship between buoyancy and displaced fluid: an immersed object is bouyed up a force equal to the weight of the fluid it displaces
Buoyancy
The apparent loss of weight of an object immersed or submerged in a fluid
Buoyant Force
The net upward force exerted by a fluid on a submerged or immersed object
Pascal's Principle
Changes in pressure at any point in an enclosed fluid at rest are transmitted undiminished to all points in the fluid and act in all directions
Pressure depends on force. Pressure is force over area.
Distinguish between pressure and force.
Liquid pressure increases with depth. Liquid pressure also increases with the density of the liquid.
What is the relationship between liquid pressure and depth of a liquid? Between liquid pressure and density?
The pressure on a submarine would double
It would be less fresh water because the density of fresh water is less than he density of salt water.
By how much does the water pressure on a submarine change when the submarine dives to double its previous depth?
If the submarine operated in fresh water, would the pressure it feels be greater or less than at the same depth in salt water?
They are the same. Pressure only depends on the depth, not the volume of water
How does water pressure 1 meter below the surface of a small pond compare with water pressure 1 meter below the surface of a huge lake?
The direction of flow would be perpendicular to the surface of the can.
If you immerse a tin can with a small hole in it in water so that water spurts though the hole, what will be the direction of water flow where the hole is?
The direction of the buoyant force is upward be use the pressure on the bottom of the object is greater than the pressure on top
Why does the buoyant force act upward for an object submerged in water?
The buoyant force and weight of a fish are the same
How does the buoyant force that acts on a fish compare with the weight of the fish?
Pressure on the sides of objects is the same and cancels out.
Why does the buoyant force on the side of the submerged objects not act sideways?
They are the same
How does the volume of a completely submerged object compare with the volume of water displaced?
Immersed means completely or partially submerged
When an object is said to be immersed in water, does this mean it is completely submerged? Does it mean it is partially submerged? Does the word immersed apply to either case?
The mass of of 1 liter of water is 1 kilogram. The weight of one liter is 9.8 newtons.
What is the mass of 1 liter of water in kilograms? What is the weight in newtons?
The buoyant force only depends on the weight of the fluid displaced by the object.
It depends on the volume of the object. The volume of the object determines how much weight of fluid is displaced.
Does the buoyant force on a submerged object depend on the weight of the object itself or on the weight of the fluid displaced by the object?
Does it depend on the weight of the object itself or the volume?
In this case the density must be the same.
When the buoyant force on a submerged object is equal to the weight of the object, how do the densities of the object and water compare?
The density of the object is less than the density of water in this case.
When the buoyant force on a submerged object is more than the weight of the object, how do the densities of the object and water compare?
The density of the object is more than the density of water in this case
When the buoyant force on a submerged object is more than the weight of the object, how do the densities of the object and water compare?
The density of the water and submarine is controlled by allowing water to flow into and out of the ballast tanks which increases and decreases the eight of the submarine.
Fish regulate their density by expanding or contracting an air sac that changes its
How is the density of a submarine controlled
How is the density of a fish controlled?
The buoyant force always depends on the volume of the water displaced by an object
Does the buoyant force on a floating object depend on the weight of the object itself or on the weight of the fluid displaced by by the object? Or are these the same for the special case of floating?
A floating ship is in equilibrium, so the buoyant force is equal to the weight of the ship- 100 tons
What is the buoyant force that acts on a 100 ton ship?