Density & Buoyancy

Density is defined as...

• Centimeters cubed per mass of substance
• Mass per unit volume of a substance
• Flow rate of a substance

Tags

NGSS.MS-PS1-2

The formula for density is...

• mass/ acceleration
• volume/ mass
• mass/ volume
• none

How do we calculate density? (with correct units!)

• ρ = m/v (in g/mL or g/cm³)
• ρ = v/m (in g/mL or g/cm²) 
• ρ=m/v (in mL/g or cm³/g) 

Buoyancy is the tendency for objects to float in a fluid. We consider buoyancy the...

• Un-gravity force 
• Anti-gravity force
• Gravitational pull
• Downwards pull on an object

True or False: Buoyancy is an upwards force measured in Newtons. 

• True
• False

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. 

Which will result in positive buoyancy?

• When the buoyant force is greater than the force of gravity
• When the buoyant force is equal to the force of gravity
• When the buoyant force is less than the force of gravity

How could you make plastic sink and steel float?

• You can't 
• Change the shape and therefore surface area 
• Remove some mass 

What is buoyant force?

• An upward force exerted by fluids on an object.
• An downward force exerted by fluids on an object.

An empty water bottle floating on the water is an example of....

• positive buoyancy
• negative buoyoncy