Chapter 4: Density and Pressure Flashcards
What is the equation relating density, mass and volume?
density = mass/volume
What is density measured in?
g/cm^3 or kg/m^3
What is the equation linking pressure, force and area?
pressure = force/area
What is pressure measured in?
Pa (1N/m^2) or N/cm^2
In what direction does pressure in a fluid act?
All directions
What factors affect pressure in a fluid?
The depth and density increase the pressure in a fluid. Surface area has no effect.
What is the equation to find the pressure in a fluid?
Pressure = mass x gravity x height/depth
How do you find the density of a regular shaped block?
Weigh the block using an electronic scale. Calculate the volume by measuring the sides and multiplying.
How do you find the density of an irregular shaped block?
Weigh the block using an electronic scale. Put the block in a known volume of water. The volume of water displaced is equal to the volume of the block.
How does an object exert pressure on the ground in terms of force and area?
Even if the force is small, if the area is small, then the pressure will be large, and so it can be more dangerous. A large force exerted over a large area can have a lower pressure.
Why can’t you have a long snorkel? (Example)
Lungs cannot expand because the pressure of the water is too high.
