Units Of Measurement Measurement Quantitative data represents quantities

Units Of Measurement

Measurement • Quantitative data (represents quantities) • Quantity: something that has magnitude, size or amount Example: o a box has a quantity that is represented by volume o A track has a quantity that is represented by meters or miles

SI Measurement • International Standards of Measurement • There are 7 SI Base Units

SI Base Units QUANTITY SYMBOL length Mass Time Temperature Amount of Substance Electric Current Luminous intensity l m t T n BASE UNIT NAME & Symbol Meter (m) Kilogram (kg) Seconds (s) Kelvin (K) Mole (mol) I Ampere (A) Iv Candela (cd)

REMEMBER • • Meters = m Liters = L Grams = g Seconds = s

SI Base Units (Common) • Mass: the quantity that measures how much matter Base: gram • Weight: A measure of gravitational pull on matter • Length: the quantity that measures distance Base: meter,

SI Prefixes • Each Base Unit can carry with it a number of prefixes • Each prefix represents a quantity larger or smaller than the Base Unit • There are 8 prefixes you need to learn

SI Prefixes

SI Prefixes • You will be asked to convert from one unit to another • The largest numbers are at the top of the chart (mega), the smallest numbers are at the bottom of the chart (micro)

SI Prefixes • When you move UP the chart from a smaller number to a larger number MOVE THE DECIMAL TO THE LEFT • When you are moving DOWN the chart from a large number to a smaller number MOVE THE DECIMAL TO THE RIGHT

Lets try It !!! • 2300 kilometers to dekameters o Decide which way to move your decimal • (Move right) • Next count how many unit difference it is from kilo to deka • 2 2300 kilometers = 230000 dekameters

Practice these next few conversions! • • • 3. 25 micrograms --> dekagrams. 00562 kiloliters --> gigaliters 33. 25 centimeters --> hectometers 650 meters --> millimeters 68520 picoliters --> deciliters

Answers • • • Decimal to left 7 places: . 000000325 dekagrams Decimal to left 6 places: . 0000562 gigaliters Decimal to left 4 places: . 003325 hectometers Decimal to the right 3 places: 650000 millimeters Decimal to left 11 places: . 00000068520 deciliters

Derived Units • Combination of units o Ex: m 2, g/m. L, etc.

Volume • Volume is a derived unit: Length x width x height Units: (m) x (m) = m 3 (cubic meter) Or (cm) x (cm) = cm 3 (cubic centimeter)

Density • Density is a derived unit: Density = mass / volume = “stuff”/”space” • Units for density could be g/L, kg/m 3 or g/cm 3 • Be sure you know which units you are using in your equation and be consistent in your answer

Density Wheel • The wheel is a quick way to determine what you are solving for Using the wheel: 1. ) Cover the variable that you are solving

2. ) Determine the formula with the remaining variables. 3. ) Multiply across in the wheel, Divide up and down in the wheel • SHOW ALL OF YOUR WORK!

m : : d x v

Common Conversion Factors • Used to convert between related measurements • Some are common to you, some are new or often forgotten • These conversions will be used in dimensional analysis to convert between units • Ex: 1” = 2. 54 cm