Solids
What is density?
The amount of mass per unit volume.
Are particles in a solid tightly packed or loosely packed?
Tightly packed.
What is pressure?
Force per unit area.
What is buoyancy?
The upward force exerted by a fluid on an object.
What happens when an object is less dense than the fluid around it?
It floats.
What type of solid structure has atoms arranged in a highly ordered repeating pattern?
A crystal
What are the two crystal structures commonly found in steel?
BCC and FCC.
Does liquid pressure depend on the shape of the container?
No
What happens if an object’s weight is greater than the buoyant force?
It sinks.
What happens when an object is more dense than the fluid around it?
It sinks.
What property describes how well a material returns to its original shape after deformation?
Elasticity
What is an inelastic material?
A material that does not return to its original shape after deformation.
At the same depth, would pressure be greater in a lake or a swimming pool?
The pressure would be the same.
What happens when buoyant force equals the object’s weight?
The object remains suspended.
A completely submerged object displaces what amount of liquid?
A volume equal to its own volume.
According to Hooke’s Law, what happens to the stretch of a spring as force increases?
The stretch increases proportionally with the force.
A beam experiences what two types of stress?
Compression and tension
What two factors determine liquid pressure?
Density and depth.
State Archimedes’ Principle.
The buoyant force on an immersed object equals the weight of the fluid displaced.
Why could the Titanic float even though it was very heavy?
Its overall density was less than water because of the air inside it.
Why are triangles used in trusses instead of squares?
Triangles are rigid and distribute loads evenly, while squares can shear into diamond shapes.
If a spring doubles its stretch, what happened to the applied force according to Hooke’s Law?
The applied force doubled.
Which location has greater pressure: 5 m deep in a lake or 1 m deep in a pool?
5 m deep in the lake.
Why would a fake gold crown displace more water than a real gold crown of the same mass?
The fake crown is less dense, so it has more volume and displaces more water.
Why did the Titanic eventually sink?
Water filled the ship, increasing its density until it became greater than water.