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Review on measuring things in science
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CAN YOU SOLVE THIS PROBLEM?
Using basic school resources, find a way to estimate the thickness of one, single sheet of paper…
1.2 DAY 2: EXPERIMENTS
How can measurements affect what we discover in science?
MAKING MEASUREMENTSThe how-to and why of measuring…
MEASUREMENTS In your lab journal,
title a new page “Measurements”
Get ruler and a “Conceptual Physics” book from the front of the room and measure it.
Draw a picture of the book and record the height, width and depth
Measure in centimeters.
height
widthdepth
MAKING A GOOD, SCIENTIFIC MEASUREMENT
In order to make a scientific measurement, you always record one decimal place more than you can know for sure.
How many decimal places should you measure using this ruler?
cm 0 1 2 3
cm 0 1 2 3
MAKING A GOOD, SCIENTIFIC MEASUREMENT
What would be a scientific measurement of this arrow?
WHAT’S THE DIFFERENCE?
What is the difference between the following measurements? 1 1.0 1.00 1.000
cm 0 1 2
cm 0 1 2 3
MAKING A GOOD, SCIENTIFIC MEASUREMENT
What would be a scientific measurement of this arrow?
cm 0 1 2 3
MAKING A GOOD, SCIENTIFIC MEASUREMENT
What would be a scientific measurement of this arrow?
THINK ABOUT IT: MEASUREMENTSDo you need to go back and
adjust the measurements you made the first time you measured the dimensions of your book?
In making these measurements, what is one way you could be precise, but not accurate?
height
widthdepth
HOW MANY BOOKS?
How many books would I need to stack them up from the floor to the ceiling?
NOW WHAT?
Working with the person next to you, find a way to estimate the thickness of one, single sheet of paper…
be quiet, people around you are listening!!!
LAB JOURNAL ENTRY: MEASUREMENTS
Writing procedures: bring in written instructions that would
explain exactly how to estimate the thickness of one sheet of paper.
Use full sentences. Write them as instructions. Make them simple instructions. Do NOT number the instructions… make a
paragraph.
This is basically practice for writing the “Procedures” section of a formal lab write up.
MEASUREMENTmeas⋅ure⋅ment [mezh-er-muhnt]
noun 1. the act of measuring. 2. a measured dimension. 3. extent, size, etc., ascertained by measuring. 4. a system of measuring or measures: liquid
measurement.
Term: Measurement My understanding: Fill in the circle that communicates your level of understanding.
Definition:
In my own words: Visual Representation: My examples:
QUANTITYquan⋅ti⋅ty [kwon-ti-tee]
–noun, plural -ties.
1. a particular or indefinite amount of anything: a small quantity of milk; the ocean's vast quantity of fish.
2. an exact or specified amount or measure: Mix the ingredients in the quantities called for.
3. a considerable or great amount: to extract ore in quantity.
Term: Quantity My understanding: Fill in the circle that communicates your level of understanding.
Definition:
In my own words: Visual Representation: My examples:
UNIT
u⋅nit /yoo-nit]
–noun
Also called dimension. any specified amount of a quantity, as of length, volume, force, momentum, or time, by comparison with which any other quantity of the same kind is measured or estimated.
Term: Unit My understanding: Fill in the circle that communicates your level of understanding.
Definition:
In my own words: Visual Representation: My examples:
WHICH UNIT?!
Which unit would you use to measure… the length of a football field? the length of a pencil? the distance across the United States? the thickness of your desk? the radius of the moon?
Why are different units useful?
What other things can we measure? What are some of the different units we could
use to measure these things?
MEASUREMENTS?!
The world grew! Countries started trading goods. Everyone had they’re own system for
measuring things… Length, for example, could be measured in…
feet, inches, miles, spans, cubits, hands, furlongs, palms, rods, chains, leagues, and
more.
What to do?!
THE METRIC SYSTEM!
In 1790, the French established a decimal based system of measuring called the metric system.
In 1960, the metric system was named the Système International d'Unités (or SI for short).
The metric system is currently used by most countries except the United States.
Changing units, or converting, in the metric system is easy, because it is based on multiples of ten…
Prefix Symbol Factorfemto- f 10-15 = 0.000,000,000,000,001pico- p 10-12 = 0,000,000,000,001
nano- n 10-9 = 0.000,000,001micro- µ 10-6 = 0.000,001milli- m 10-3 = 0.001centi- c 10-2 = 0.01deci- d 10-1 = 0.1
Base Units 100 = 1deka- da 101 = 10hecto- h 102 = 100kilo- k 103 = 1,000
mega- M 106 = 1,000,000giga- G 109 = 1,000,000,000tera- T 1012 = 1,000,000,000,000peta- P 1015 = 1,000,000,000,000,000
THE METRIC SYSTEM!
Because the metric system is based on powers of ten, it is very easy to convert… 1 gram = 1,000 milli-grams 1 meters = 1,000 milli-meters 1 liter = 1,000 milli-liters
The prefix holds the same value in the metric system… 1,000 grams = 1 kilo-gram 1,000 meters = 1 kilo-meter 1,000 liters = 1 kilo-liter
So, if you know the value of the prefix, you can convert any metric unit!
CONVERTING NON-METRIC UNITS…
How do I go from one set of units to another? What if you are trying to make a recipe that calls
for milliliters, but you only have teaspoons, tablespoons and cups?
What if you go on a trip to Europe and all the speeds and distances to the next city are posted in kilometers per hour (km/h) and kilometers, not miles per hour and miles?
What if your crazy physics teacher wants you to tell them how many millimeters are in a mile?
There are several methods… I will show you my favorite!