1. Matter and Energy Energy = Capacity to do work W = FD
W = Work (ML2/T2)
F = Force (ML/T2)
D = Distance (L)

2. Force
F = ma
F = Force (ML/T2)
m = mass (M)
a = acceleration (L/T2)

3. SI and English Units SI: - Mass = kilogram - Length = meter
- time = second
English
- Mass = slug
- Length = foot

4. Force: SI vs English SI => Newton = 1 kg m/s2 Acceleration = m/s2
English => force = pound (lb) = slug-ft/s2

5. Weight of a body W = mg (ML/T2) m = mass (M) g = acceleration (L/T2)
Mass of body in which weight = 1 Newton: m =w/g = 1 Newton/9.8 m/s2 = kg.

6. Density of a fluid
ρ = m/v (M/L3)
m = mass (M)
v = volume (L3)

7. Specific Weight γ Weight per unit volume (N/m3; lb/ft3)
γ = w/v (M/L2T2)
γ = w/v = mg/v = ρg

8. Pressure Pressure = Force per unit area P = F/A (M/LT2) (N/m2; lb/ft2)
Force F => (ML/T2)
Area A => (L2)

9. Pressure – cont. P = F/A (M/LT2) (N/m2 = Pascal; lb/ft2)
Hydrogeology: P is relative to atmospheric pressure (1.013 x 105 Pa or 2116 lb/ft2)

10. Viscosity
Water => Newtonian fluid => resistance to motion is proportional to dynamic viscosity μ.
μ units N s/m2 (Pa s) or lbs/ft2.

11. Bulk modulus or compressibility
Water is a compressible fluid.
Pressure applied => V reduced => density increases.
K = ΔP / (ΔV/V)
K is bulk modulus or proportionality constant.
K units (N/m2 or Pa) => same units as pressure

12. Bulk Modulus = (DP/Q)
… where Q = dilatation = DV/V
and P = pressure