Practical assessment

Question 1

What is stokes law?

Answer 1

V = (p1-p) x g x d2/ 18u

V = settling velocity
p1-p = density difference between particle and fluid
g = acceleration due to gravity
u = viscosity
d = diameter of particle

Question 2

what assumptions are made about stokes law?

Answer 2

• settling velocity increases with increasing diameter size
• settling velocity increases with denser particles

Question 3

how do we calculate temperature with depth

Answer 3

(highest temp - lowest temp)/ (highest depth - lowest depth) x 1000

ensure depth is in km

Question 4

what is the equation for lithostatic pressure?

Answer 4

Lithostatic pressure = depth (m) x average lithostatic density (g/cc) / 10

10 is a conservation factor

Question 5

what is the correct units for pressure?

Answer 5

kg/cm2 = old unit
Pa = pascals new unit

1 kg/cm2 = 98066.5 Pa

Question 6

what is the equation for hydrostatic pressure?

Answer 6

Hydrostatic pressure = height if water column (m) x density of fluid (g/cm-3) / 10

density of water = 1.1 g/cm-3

Question 7

what is the equation for over pressure?

Answer 7

over pressure = measured pressure - hydrostatic pressure

Question 8

what is the equation for porosity?

Answer 8

Porosity = Vpore / Vbulk

Question 9

what us the equation for Vgrain?

Answer 9

mass (g) / grain (g/cm3)

Question 10

how to calculate porosity if we do not have pore

Answer 10

Vpore/ Vbulk = (Vbulk - Vgrain)/ V bulk

answer in cm3

Question 11

how to work out atomic mass of a formula?

Answer 11

number of elements x atomic mass

Question 12

equation for mass?

Answer 12

mass = volume x density

Question 13

equation for volume?

Answer 13

length x width x height

Question 14

equation for grade?

Answer 14

mass x grade (g/t)

Question 15

equation for density?

Answer 15

p = mass / volume

Question 16

grain volume equation?

Answer 16

Vpore = Vbulk - Vgrain

Question 17

volume of a cylinder?

Answer 17

V (SI cm) = pie x radius 2 x height