5 - solids, liquids and gases a) units b) density and pressure

Question 1

5.1 use the following units: degrees Celsius (oC), Kelvin (K), joule (J), kilogram/metre3 (kg/m3), kilogram/metre3 (kg/m3), metre (m), metre2 (m2 ), metre3 (m3), metre/second (m/s), metre/second2 (m/s2 ), newton (N), Pascal (Pa).

Answer 1

Unit of temperature: degrees Celsius (oC)
Unit of temperature: Kelvin (K)
Unit of mass: kilogram/metre3 (kg/m3)
Unit of density: kilogram/metre3 (kg/m3)
Unit of distance: metre (m)
Unit of Area: metre2 (m2)
Unit of Volume: metre3 (m3)
Unit of Speed: metre/second (m/s)
Unit of Acceleration: metre/second2 (m/s2)
Unit of force: newton (N)
Unit of Pressure: Pascal (Pa)

Question 2

5.2 know and use the relationship between density, mass and volume:

Answer 2

density=mass/volume

p=m/V

Question 3

5.3 describe experiments to determine density using direct measurements of mass and volume

Answer 3

Suppose a rectangular block have a volume of 50 m3 and mass of 200kg. Its density will be 200/50 kg/m3, i.e. 4kg/m3.

Question 4

5.4 know and use the relationship between pressure, force and area:

Answer 4

ρ=force/area

p=F/A

Question 5

5.5 understand that the pressure at a point in a gas or liquid which is at rest acts equally in all directions

Answer 5

Pressure in liquids and gases act equally in all directions, as long as the liquid or gas are not moving.

Question 6

5.6 know and use the relationship for pressure difference:

Answer 6

pressure difference = height × density × g

p = h × ρ × g