Measurement & the Metric System Monday, August 3 rd, 2015

The dimensions, capacity, or amount of something – Time – Temperature – Length – Volume – Mass Measurement

Measurement Definitions Mass - the amount of matter Volume - the 3D space matter occupies Temperature - the average heat of the particles in matter Length - the longest linear dimension of matter

When we measure, we use a measuring tool to compare some dimension (amount) of an object to a standard, an exact quantity that is agreed upon for comparison. Standards of Measurement

The Metric System Based on multiples of ten Uses “base units” – Time: second (s) – Temperature: Kelvin (K) – Length: meter (m) – Volume: liter (L) – Mass: gram (g)

All of these are directly measured

Identify the measurement in metric units. 1. John’s height is A) 1.5 yards B) 6 feet C) 2 meters 2. The volume of saline in the IV bottle is A) 1 liters B) 1 quart C) 2 pints 3. The mass of a lemon is A) 12 ounces B) 145 grams C) 0.6 lbs Learning Check

Identify the measurement in metric units. 1. John’s height is A) 1.5 yards B) 6 feet C) 2 meters 2. The volume of saline in the IV bottle is A) 1 liters B) 1 quart C) 2 pints 3. The mass of a lemon is A) 12 ounces B) 145 grams C) 0.6 lbs Learning Check

The Prefixes The metric system uses “prefixes” to modify the base units. For example, a centimeter is 0.01 of a meter. 1 cm = 0.01 meters

1. Length a. The distance from one point to another point. b. Base unit is the meter (m). c. Tool is the metric ruler. 2. Volume a. The amount of space a substance occupies. b. Base unit is the liter (L). c. Tool is the graduated cylinder.

3. Mass a. The amount of matter in a substance. b. Base unit - gram (g). c. Tool is the balance (triple beam or electronic)

Using the Tools A. 65 mL B mL C. 75 mL D. 50 mL E. 50 mL

A. 48 mL B. 45 mL C. 38 mL D. 27 mL E. 18 mL F. 7 mL

Significant Figures and DOUBT Always go one digit past where the measuring tool is incremented for. This is known as reasonable doubt. For example:

The Importance of Units NASA: Human error caused loss of the Mars Orbiter on November 10, 1999 WASHINGTON (AP) -- Failure to convert English measures to metric values caused the loss of the $125,000,000 Mars Climate Orbiter, a spacecraft that smashed into the planet instead of reaching a safe orbit, a NASA investigation concluded ``The root cause of the loss of the spacecraft was a failed translation of English units into metric units..." said Arthus Stephenson, chairman of the investigation board.

You are driving to find a friend’s house and get lost - Google Maps is not working!!! You stop and ask a stranger walking his dog for directions, and he seems to know where you want to go. “ Take a left at the next stoplight, and then go five.” Complete the sentence on your own without consulting anyone else. Take a left at the next stoplight, and then go five _________________________.

OK... Yes units are important! But what do you do if you are unfamiliar with the unit of measurement? It helps if you can relate it to something else... Units of measurement can be related through the use of an equivalency, or conversion factor. An equivalency is a mathematical statement of the relationship between two different units of measurement. ex) 1 m = 100 cm A conversion factor is a rearranged form of the equality used to convert one unit of measurement to the other by simple multiplication.