Presentation on theme: "Types of quantitative observations. International System of Units 1. Known as SI units (System International) – Official name of the metric system. –"— Presentation transcript:
Types of quantitative observations
International System of Units 1. Known as SI units (System International) – Official name of the metric system. – Is an “universal system of measurement” in the scientific world. – What does “Universal” mean? Used by all scientist worldwide regardless of their language.
Why does science need an universal system of measurement? (think of the scientific method) – Step 6 of the scientific method – Results of an experiment must be able to be replicated by other scientist Metric system is also easier to used. Why? – Based on multiples and divisions of 10
2. The metric/SI system is also easier to use. – Why? You only need to move a decimal point to the left or to the right.
Length: distance between 2 points SI base unit = meter Instrument used to measure length? metric ruler or meter stick Divisions of a meter = dm, cm, mm Multiples of a meter = Km, Hm, Dm
Answers: Length Height 1. Measure the length of this rectangle in centimeters: 2. Measure the height of this rectangle in centimeters: 3. Measure the length of this line in millimeters:
Conversions Kilo Hecto Deca BASE deci centi milli UNIT King Henry died----gulp----drinking chocolate milk -Changing from one unit to another. - Uses prefixes to describe divisions and multiples of a base unit.
Metric –vs- English Conversions Kilo Hecto Deca BASE deci centi milli UNIT Easier: 10 Kilometers = how many meters? 500 centimeters = how many meters? Harder: 10 miles = how many inches? 10 Km move decimal 3 places to right = meters 500 cm move decimal 2 places to left = 5. meters 10 miles x 5280 feet x 12 inches = 6336 inches 1 mile 1 foot
AREA What is the area of an object? L x W = meters squared 5 cm 10 cm = 50 cm2
Solid volume: – How much space an object occupies – LxWxH = m3
Temperature SI base unit = degrees Celsius Instrument used to measure: Thermometer Therm = heat
Let’s do a comparison: CELSIUS VS FAHRENHEIT WATER BOILS BODY TEMP ROOM TEMP WATER FREEZES ° C x 9/ = °F (°F - 32) x 5/9 = °C
BOILING ROOM TEMP FREEZING BODY TEMP 37 C98.6 C 22
Volume How much space an object occupies. Two types of volume: Liquid and solid Liquid volume: SI base unit = liter (Kl, Hl, Dl, l, dl, cl, ml)
Instrument used to measure liquid volume? Graduated Cylinder Flask Beaker Graduated Cylinder
Read the bottom of the meniscus. = 43 ml
Solid Volume: Amount of space an object occupies. Length x Width x Height SI label: m3 or cm3
Not all solids have a regular shape!! Sometimes the length, width and height can not be determined Regularly shaped Irregularly shaped
Solid volume of a irregular shaped object – Use water displacement to determine volume
Water Displacement Record volume of water in graduated cylinder. 7ml Add object Record volume of water after object is added. 9ml The difference is the volume of the object 2ml Change unit to cm3 Answer: 2 cm3
Mass The amount of matter in an object. SI unit: -grams (Kg, Hg, Dg, g, dg, cg, mg) Instrument or tool to used to determine mass? -Balance
Mass is different than weight Mass is a constant value, it is not influenced by the pull of gravity. Weight is based upon the pull of gravity. The pull of gravity varies based on an objects distance from the center of the Earth.
Sea level Top of mountain Mass: 68 Kg Weight: 150 pounds Mass: 68 Kg Weight: 147 pounds Mass stayed constant Weight decreased due to a lesser pull of gravity.
Density: – The mass of an object per unit volume. mass / volume = – g/L (liquid density) – g/m3 (solid density)
Density Determination 1 Kg of Feathers 1 Kg of Stones Mass of feathers = 1 Kg Volume of feathers = 100 m3 Density = mass = 1 Kg =.001 volume 1000 m3 Mass of stones = 1 Kg Volume of stones = 10 m3 Density = mass = 1 Kg = 2 volume.5m3
More or less dense????? Less dense than the liquid More dense than the liquid