Buoyancy

This is what happens to an object when the gravitational force is stronger than the buoyant force.

​ (a)  

• It will float

• It will sink

This is what happens to an object when the buoyant force is stronger than the gravitational force.

​ (a)  

• It sinks

• It floats

True or false. If something has buoyancy it is able to float.

• True

• False

 Whose principle says buoyant force = the weight of the fluid an object displaces 

• Archimedes

• Pascal

• Bernoulli

• Einstein 

Why does a steel ship float, while a block of the same steel sinks?

• shape of object

• air is lighter than water

• the block's buoyancy is less than its weight

• all of the above

Why do boats float?

• The material they are made up of.

• Their volume gives them a large density.

• Their hollow shape leads to a low density.

• The number of passengers is not too high.

A helium balloon floats in air because

• there is more air than helium.

• helium is equally dense as air.

• helium is less dense than the air.

• helium is as dense as the air.

An object will rise up in a fluid if

• Gravity and buoyant force equal

• Density of object and fluid is equal

• The buoyant force is stronger than gravity

• If the density of the object is greater than the fluid

Archimedes' Principle states that... 

• The buoyant force acting on an object equals the volume of the fluid displaced by the object.

• The buoyant force acting on an object equals the weight (force of gravity) of the fluid displaced by the object.

• The buoyant force acting on an object will always be equal. 

Some things that will float in water are:

• a solid clay ball and a lacrosse ball

• rocks and ceramic weights

• a textbook and a pebble

• a cork and a medicine cup