# To What Extent Is Climate Change a Bigger Global Threat Than Terrorism? Essay

1227 WordsMay 15, 20135 Pages
Measurement Base quantities and their units; mass (kg), length (m), time (s), current (A), temperature (K), amount of substance (mol): Base Quantities | SI Units | | Name | Symbol | Length | metre | m | Mass | kilogram | kg | Time | second | s | Amount of substance | mole | mol | Temperature | Kelvin | K | Current | ampere | A | Luminous intensity | candela | cd | Derived units as products or quotients of the base units: Derived | Quantities Equation | Derived Units | Area (A) | A = L2 | m2 | Volume (V) | V = L3 | m3 | Density (ρ) | ρ = m / V | kg m-3 | Velocity (v) | v = L / t | ms-1 | Acceleration (a) | a = Δv / t | ms-1 / s = ms-2 | Momentum (p) | p = m x v | (kg)(ms-1) = kg m s-1 | Derived Quantities | Equation | Derived Unit | Derived Units | | | Special Name | Symbol | | Force (F) | F = Δp / t | Newton | N | [(kg m s-1) / s = kg m s-2 | Pressure (p) | p = F / A | Pascal | Pa | (kg m s-2) / m2 = kg m-1 s-2 | Energy (E) | E = F x d | joule | J | (kg m s-2)(m) = kg m2 s-2 | Power (P) | P = E / t | watt | W | (kg m2 s-2) / s = kg m2 s-3 | Frequency (f) | f = 1 / t | hertz | Hz | 1 / s = s-1 | Charge (Q) | Q = I x t | coulomb | C | A s | Potential Difference (V) | V = E / Q | volt | V | (kg m2 s-2) / A s = kg m2 s-3 A-1 | Resistance (R) | R = V / I | ohm | Ω | (kg m2 s-3 A-1) / A = kg m2 s-3 A-2 | Prefixes and their symbols to indicate decimal sub-multiples or multiples of both base and derived units: Multiplying Factor | Prefix | Symbol | 10-12 | pico | p | 10-9 | nano | n | 10-6 | micro | μ | 10-3 | milli | m | 10-2 | centi | c | 10-1 | decid | d | 103 | kilo | k | 106 | mega | M | 109 | giga | G | 1012 | tera | T | Estimates of physical quantities: When making an estimate, it is only reasonable to give the figure to 1 or at most 2 significant figures since an estimate is not