Section 2: Standards of Measurement Chapter 1 Section 2: Standards of Measurement

Measurement What is measurement and why is it important? It is the comparison of an object to a unit. The number of units that characterizes the object is referred to as it’s measure. Measurement allows us to compare or describe the size of objects in our environment. What are some common concepts of size?

Measurement System is a man-made technique or method for describing size concepts of our environment with numbers. A standard is an exact quantity that people agree to use for comparison. Why is it important to have standard, well defined units of measurement? Standards make it possible for different people to accurately compare measurements.

System of Measurement What system of measurement are you most familiar with? English or Metric? English Metric Length Foot, Inch, Mile, Block Meter, Centimeter, Kilometer Volume Gallons, Cups, Ounces Liter, Milliliter Weight Pounds, Tons Gram, Kilogram Temperature Fahrenheit Kelvin (K), Degree Celsius (°C) Time Seconds, Minutes, Hours Second, Kilosecond, Millisecond

History What units of measurement did early man use? The distance between the nose and outstretched arm A pace or step of a man A man’s foot The girth of a man A pinch

In one country….. 5ft = 1 double pace 1 mi = 1000 double paces 10 fingers width = one span 1 fathom = 6ft A girth = 1yard Every country had their own system and each one was different from the other.

SI In 1960, a universal system of measurement was devised. This system was based on the metric system (developed in the late 1700’s) and become known as: The International System of Units (SI). All SI standards are universally accepted and used by scientists. Each type of measurement has a base unit. Based on units of 10.

SI—Metric Base Units Length—Meter (m) is the base for length Mass—Kilogram (kg) is the base for mass Volume—Liter (l) is the base for volume Time—Second (s) is the base for time Temperature—Both K and °C are bases for tmeperature

SI—Metric Prefixes and Abbreviations Meaning Kilo k 1000X or 10³ Hecto h 100X or 10² Deka da 10X or 10¹ Base Unit m, l, g 1 Deci d .1 or 10-1 Centi c .01 or 10-2 Milli m .001 or 10-3 Micro µ .000 001 or 10-6 Nano n .000 000 001 or 10-9 Kings Have Diamonds But Diamonds Cost Money

Differences Between the Two Systems Metric 10mm = 1cm 100cm = 1m 1000m = 1km English 12in = 1ft 3ft = 1yd 8oz = 1 cup 5280ft = 1mi 32oz = 1qt Each unit on Metric scale is 10 times more than the unit below it.

Converting from one unit to another in the English System How many feet are there in 2 mi? 2mi x 5280ft = 10, 560ft 1 mi How many inches are there in 1 mi? 1mi x 5280ft x 12in = 63,360in 1mi 1ft

Converting from one unit to another in the Metric System Finding equivalent metric measurements: kb hb dab b db cb mb kb hb dab b db cb mb Each unit on the metric scale is 10 times more than the unit below it.

km hm dam m dm cm mm When changing from a larger unit to a smaller unit, count the number of steps on the scale from the starting position to the finish position and move the decimal in the same direction, and same number of spaces 30 km = 30000m (3 spaces to the right) 22.4 hm = 2240m (2 spaces to the right)

km hm dam m dm cm mm When changing from a smaller unit to a larger unity, count the number of steps on the scale from the starting postion to the finish postion and move the decimal in the same direction and same number of spaces to the left. 30 m = 0.030 km (3 spaces to the left) 22.4 dm= 0.0224 hm (3 spaces to the left)

You can also use the unit cancel method: 30km x 1000m = 30000 m 1km 10cm x 1m = 0.1m 100cm

Measuring Distance An important idea to keep in mind when measuring something is that you should choose the appropriate unit when doing so. If you are measuring something huge use meters or kilometers over centimeters or millimeters.

Volume Volume is the amount of space occupied by an object. When measuring a solid, volume is LxWxH H W L

When measuring the volume of a liquid you are actually indicating the capacity of the container that holds that amount of liquid The most common units for liquid volume are liters and milliliters. A liter occupies the same volume as a cubic decimeter, dm³

Matter Mass is the measurement of the quantity of matter in an object. Matter is measured in grams, g. This can also be considered what we find when we weigh an object on earth.

Density Density is the mass per unit volume of a material. You divide the object’s mass by it’s volume. This leaves you with a derived unit of g/cm³ This is an important concept for buoyancy, whether or not an object will float or sink

Time and Temperature Time is defined as the measurement of the interval between two events. The SI unit of time is seconds, s. Temperature is how hot or cold something is. The SI unit of temperature is K.

To find K from ˚C simply add 273 to the Celsius temperature, because they have the same size units. 0K is the coldest temperature in the universe. It is known as absolute zero and is -273˚C. Remember that 0˚C is the freezing point of water and 100˚C is the boiling point.