Density and Buoyancy Review

Looking at the image... can oak float in water? 

• Yes
• No

Tags

NGSS.MS-PS1-2

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

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

True or False: Volume is the amount of matter in a substance. Mass is the amount of space a substance takes up. 

• True
• False 

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

Tags

NGSS.MS-PS2-4

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