Hydrostatics. Archimedes' principle

What is Archimedes' Principle?

• The buoyant force is equal to the weight of the object

•    The buoyant force is equal to the gravitational force of the fluid

•     The buoyant force is equal on all sides of a submerged object

•    The buoyant force is equal to the weight of the fluid displaced

If the weight of an object that is submerged in a fluid is 10 N and the buoyant force on it is 20 N, what will happen to the object?

•    It will sink

•   It will float

•    It will remain in equilibrium

•    More information is needed

Pressure in a liquid depends on the __________.

•   depth of the measuring point.
  

• 
  volume of the liquid.
  

• 
     mass of the liquid.
  

• 
  density of the liquid.
  
  

• 
    both A and D

Water pressure on a submerged object is greatest against the __________.

• bottom of the object

• Water pressure is the same against all surfaces of the object

• sides of the object

• top of the object

The reason a life jacket helps you float is that _________.

• the jacket repels water

• the jacket has the same density as an average human

• the jacket makes you weigh less

• you and the jacket together have density less than your density alone.

Lobsters live on the bottom of the ocean. The density of a lobster is __________.

• greater than the density of seawater

• equal to the density of seawater

• less than the density of seawater

The density of a submerged submarine is about the same as the density of __________. 

• iron

• a floating submarine

• a crab

• water

The reason objects immersed in a fluid experience an upward buoyant force is because fluid pressure on the bottom of the object is greater than fluid pressure on the top of the object.

•    False

•   True

An egg is placed at the bottom of a bowl filled with water. Salt is slowly added to the water until the egg rises and floats. From this experiment, one can conclude that

• buoyant forces do not always act upward.

•     the density of salt water exceeds the density of egg.

•   calcium in the eggshell is repelled by sodium chloride.

A kilogram of lead and a kilogram of aluminum are submerged in water. The buoyant force is __________.

• greater on the aluminum.

•    greater on the lead.

•   the same on each