Density and Pressure

Question 1

What is the relationship between density, mass and volume?

Answer 1

Density = Mass/Volume
ρ = M/V

Density is measured in g/cm³ or kg/m³ ect.

Question 2

How do you measure the volume of an irregular object?

Answer 2

Place it in a liquid, and measure the volume of liquid displaced

Question 3

What is the relationship between pressure, force and area?

Answer 3

• Pressure = Force/Area
• P = F/A

So force acting on a small area results in a much higher pressure than a force acting on a large area

Question 4

How does pressure at a point in a gas or liquid (fluid) work?

Answer 4

• It will be exerted evenly in all direction
• It causes a force to be exerted at right angles to any surface within the fluid

Question 5

What is the relationship between change in pressure, height, density and gravitational field strength when working out pressure below liquid?

Answer 5

• Change in pressure = Height (below surface of liquid) x Density (of liquid) x Graviational Field Strength (10)
• p = h X ρ X g

Remember that this is the change in pressure, you would still need to add atmospheric pressure to find the total pressure below water