conceptual Physics - The Metric System
Day 1 | Day 2 - 3 | Lab | Reading Assignment

This Unit's

Process Standards: 1.1, 1.3, 3.3, 3.5, 6.3
Content Standards: 1.3
Instructional Technology Standards: 2.1, 4.2, 4.3

vocabulary for the week
  • Measurement
  • Standard
  • SI
  • Meter
  • Liter
  • Gram
  • Celsius
  • Kelvin
  • Fahrenheit
  • Mega
  • Kilo
  • Centi
  • Milli
  • Base units
  • Derived units


Systems of Measurement

a ruler graduated in millimeters

click to find the answer to today's question How many grams are in a kilogram?

An introduction to measurement. link to an Internet Website

Why do we need a measurement system?link to an Internet Website When experiments are performed there are almost always some observations where questions like "how fast", "how far", or "how much" must be answered. The only way to answer these questions is through measuring. Because of this, numbers in science will always have "units". These units are just as important as the numbers when communicating observations. Never write a number without its units.

A "standard" is something that is used as a comparison for measuring.

Two things are important for any standard:

  1. The standard must be available for everyone to use when checking measurements. This means a standard should be something in nature that is the same all over the earth.
  2. The standard must never vary.

The English System of Measurement is commonly used as the day to day system in the United States. Since we are familiar with this system, we know about pounds, feet, and gallons. But what are the standards for these units? Because there are no standards in nature for these units, the rest of the world has moved to another measurement system.

It might be alright to use the English System when communicating with others in the United States, but what about communicating with the rest of the world? Scientific discoveries are made all over the world. It is important that observations made in one country can be verified by someone in another country. For this reason, science observations must be measured using standards that are available around the world.

The International System of Measurement - SI link to an Internet Website is commonly called the metric system in the United States. Each of the units within this system has an unchanging standard found in nature all over the earth. All science measurements are made using this system.
link to an Internet website with information about the standards

Unit Conversion Calculator link to an Internet Website
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Some of the common SI unit relationships used in science classes:
    1 liter = 1 cubic decimeter (dm3)
    1 cubic centimeter (cm3) = 1 milliliter (ml)
Refer to these guidelines for correct use link to an Internet Website to avoid common mistakes when using the International System of Units.

Derived units are combinations of basic units. You can see that the volume units above are combinations of length units. This makes volume a derived unit. Density is another derived unit that will be used in this class. Density is found by dividing mass by volume and is usually expressed in grams per cubic centimeter.

Using the Metric System is difficult only because:

There are exact conversion factors that can be used to change units in one system to units in the other. We will not stress conversion between the systems in this class. All our measurements will be done using SI units. The table below might help you begin to visualize the size of the units of the metric system.

An approximate comparison of the two systems:

English System Metric System
1 yard 0.9 meter
1 mile 1.5 kilometer
1 pound 0.5 kilogram
1 quart
4 quarts = 3.8 liters
~1 liter

Did you use the Lab Key last week? As the labs become more difficult, the Keys will become more important to your success. The Lab Keys are here to help, but you must use them to plan what you will do in the lab before you come to class on lab day. link to a local webpage with useful information
In-Class Assignment 021:
This assignment must be turned in by the end of class today to receive credit.
Scoring criterialink to a local webpage

  1. Use the "tip" above to answer these questions.
    1. It is about 10 miles to Poteau. How far is that in kilometers?
    2. What is the mass of a five pound bag of sugar in kilograms?
    3. A distance is measured as 3,000 feet. What is that in kilometers?
    4. A football field is 100 yards long. How many meters is that?
    5. How many liters are in one gallon?
  2. What is absolute zero?
  3. What is the freezing point of water on the Kelvin scale?
  4. How many grams are in one kilogram?
  5. How many centiliters are in one liter?
  6. What is the standard for the SI meter?

Day 2 - 3

click to find the answer to today's question What is a "first person statement"?

To "do" science, one must be able to find, evaluate, and use information. Your ability to be a good "scientist" depends on your ability to think about the facts and find ways to apply them. No one can tell you what to think. It's up to you!

During your years of school so far you have learned lots of facts. Some of those facts are basic and unchanging, but many of the things you know about the world are incomplete. High School students are expected to use more complex facts than middle school students. When you go to college, you will be expected to use more complex facts than a high school student. To make a grade of "A" in physical science class, you must add to the complexity of the facts you use. To demonstrate your understanding of what you learn this year, you will be asked to put things into your own words, not just copy down information.

As this year progresses, you will be asked to do more and more complex research. Learn to use all the resources that are available to you. The most important information for each concept will be found in the weekly pages on The Science Room website. The Science Room has links to most of the Internet resources you will need.

Think of yourself as a detective. The facts are out there - it's up to you to find them and use them to solve problems. Good detectives find all the facts, but it takes a great detective to put those facts together to solve the tough problems.

In-class Assignment 023:
This assignment must be turned in by the end of class tomorrow to receive credit.

  1. There are several ways to record and apply your research. One of those is to write an essay explaining your research and your ideas about it. Here is a page that gives you information about science to a local webpage
  2. Use this essay planning guidelink to a local webpage for your first science essay.
  3. Before beginning your essay, study this essay evaluation to a local webpage The rubric tells you how to make a good score.
  4. After writing the essay, complete the self-evaluation portion of the rubric.
    • If any weeknesses in your essay are identified by the rubric, fix them before turning in the assignment.

    Turn in both the essay and the evaluation rubric to your science facilitator.
    Always staple rubrics on top of assignments.

Research Links:

Conceptual Physics


There are 1000 grams in a kilogram.
The prefix "kilo" means 1000. This prefix is one of several that everyone must know.


A "first person statement" directly refers to the person making a statement. It includes words like I, my, and we.
First person statements should never be used when you write paragraphs, essays, and scientific papers.