Topic 4 - Materials

Question 1

Density

Answer 1

ρ = m / v
Where ρ= density in kg/m ³
m= mass in kg
v= volume in m ³

Question 2

Stokes Law

Answer 2

F = 6 𝜋 η r v
Where η= coefficient of viscosity in pa s
r= radius of sphere in m
v= velocity of sphere in m/s

Question 3

Hookes law

Answer 3

F = k e
Where F= force exerted on spring in Newtons
k= spring constant in N/m
e= extension in m

Question 4

Stress

Answer 4

σ = F / A
Where σ= stress in N/m ²
F= force in N
A= area in m ²

Question 5

Strain

(Equation)

Answer 5

ε = e / L
Where ε= strain (no units)
e= extension in m
L= original length in m

Question 6

Young’s modulus

(Equation)

Answer 6

E = σ / ε
Where E= Young’s modulus in pa
σ= stress in N/m ²
ε= strain (no units)

(Equation)