**Conceptual Physics:** Measurement and the Language of Physics Units

This topic contains a selection of units designed to help you to teach physics. In physics, using precise measurements and standard units is important in comparing physical quantities and understanding basic concepts.

### Physics Terminology (2)

#### Activities:

If you've never visited the award-winning *Hyperphysics* web site, put it on your list. It is a set of online tutorials that features concept maps laid out in a web-like fashion for easy navigation. This page describes units of measurement, unit conversions, dimensional analysis, and basic mechanical quantities. Some of the maps are "active graphics", which link to capsules of background information. Remarkably easy to use!

**Item Type:**Reference Material

**Level:**Teacher Support

#### Student Tutorials:

To a beginning student, the unfamiliar language of physics can seem like a foreign tongue. This tutorial, part of the respected *Physics Classroom* collection, is an interactive introduction to some basic terminology. It focuses on scalars, vectors, distance, and displacement.

**Item Type:**Interactive Tutorial

**Level:**Grades 9-12

**Duration:**30 minutes

### Units of Measure (5)

#### Activities:

This is a set of free tutorials on error and uncertainty, best-line-fit, measurement of slope in statistical representations, quantization error, and sampling frequency. It provides rules and "how-tos" for calculating both relative and absolute uncertainty in a measurement.

**Item Type:**Tutorial

**Level:**9-12

This resource is a digital tool for performing unit conversions with the extra feature of displaying cancellation of terms, helping students to gain a deeper understanding of the mathematical processes involved. Students can convert among 25 physical quantities, including units such as force, temperature, energy, and current.

**Item Type:**Mathematical Tool

**Level:**Grades 6-12

#### References and Collections:

All mechanical quantities can be expressed in terms of three quantities: length, mass, and time. This resource from *Hyperphysics* describes units of measurement, unit conversions, dimensional analysis, and basic mechanical quantities. Some of the maps are "active graphics", which link to capsules of background information. Remarkably easy to use!

**Item Type:**Reference Material

**Level:**High School

NIST, the National Institute of Standards and Technology, publishes this set of in-depth reference materials, covering 3 topics: 1) Fundamental physical constants, 2) International System of Units (SI), and 3) Uncertainty in measurement.

**Item Type:**Reference Material

**Level:**Teacher Support

Teachers will find in-depth information on base units, derived units, and relationships among SI units in this free web site developed and maintained by NIST (the National Institute for Science and Technology). Don't miss the link to the "Digital Dutch" unit converter. It is amazingly easy to use.

**Item Type:**Reference Material

**Level:**Teacher Support

### Applying Measurement in Physics (9)

#### Lesson Plans:

This 3-day inquiry-based lesson is a great way for students to discover what "accuracy" and "precision" mean in measurement. Fun hands-on activities include measuring objects using ancient "cubit" units and tossing foam darts to gather data. The lesson concludes as students work cooperatively to explore using significant figures. *Includes analysis questions and data tables.*

**Item Type:**Cooperative Learning

**Level:**Grades 7-12

**Duration:**3 class periods

#### Activities:

This free digital grapher is especially user-friendly for beginning learners. Students can choose from five graph types: bar, line, area, pie, and X/Y. Various patterns, colors, grids, and label choices are available to allow customization. Minimum and maximum values can be set to limit the scale of the graph.

**Item Type:**Graph-Making Tool

**Level:**Grades 4-12

After introducing the rules of significant figures, students can test their skills in this interactive drill & skill. We suggest setting up cooperative learning groups to make it a game. *NOTE FROM THE EDITOR: beginning students often misunderstand or overestimate the usefulness of significant figures. In real-world research laboratories, practicing scientists commonly express uncertainty quantities as a separate numeral. Good examples of how to express uncertainty can be found in the NIST Fundamental Physical Constants (Reference below).*

**Item Type:**Problem Set

**Level:**High School

**Duration:**30 minutes

This is a really nice interactive simulation to give students virtual practice in using a micrometer, a device for doing ultra-precise measurement down to the level of 1 micrometer. Each time the "reset" button is pressed, a random-size object appears on screen. Students use sliders to move the object into place, perform the measurement, and check the accuracy of their reading.

**Item Type:**Interactive Simulation

**Level:**Grades 7-12

**Duration:**30 minutes

This Java-based activity lets students manipulate a 3-D rectangular prism or triangular prism to explore surface area and volume. It's designed to help secondary students visualize the relationship of width, depth, and height in calculating and estimating volume/surface area.

**Item Type:**Interactive Simulation

**Level:**Grades 5-10

**Duration:**30 minutes

#### References and Collections:

Values of the fundamental physical constants, recommended for international use, are provided at this web site. These are the latest values of the constants recommended by CODATA. Need background information? It's all there, in an easily-searchable format. **Note:** CODATA adjustment based on the recently revised SI is under review in 2018. By 12/31/2018, changes will be made that will significantly affect the uncertainties of many constants.

**Item Type:**Reference Material

**Level:**Grades 9-12

#### Student Tutorials:

This item, part of the Open Door website, discusses the role of uncertainty in measurement. Students learn the difference between systematic and random error, and gain practice in quantifying the error. Also find high-quality sections on the Vernier scale, "best-fit line", and sampling frequency.

**Item Type:**Online Tutorial

**Level:**High School

**Duration:**One class period

Measurement of physical objects is, by nature, imprecise. When rounding numbers, you must use enough digits to minimize errors. However, if too many digits are used, errors can be easily made keeping track of all the numerical values. This tutorial will help students with the basic rules.

**Item Type:**Interactive Tutorial

**Level:**High School

**Duration:**30 minutes

Converting between units doesn't have to be frustrating to your students. This tutorial, part of an award-winning collection, is the best we found for demonstrating how to use unit cancellation to solve problems involving unit conversions.

**Item Type:**Online Tutorial

**Level:**Grades 8-12

### For the New Teacher (4)

#### Activities:

This digital unit converter offers students more than the typical online conversion resource. It allows conversion among 25 physical quantities, from more common applications (force, energy, current, voltage) to lesser-used conversions such as illuminance and magnetic flux. It provides the additional feature of displaying cancellation of terms, helping beginners to gain a deeper understanding of the mathematical processes involved.

**Item Type:**Mathematical Tool

**Level:**Grades 6-12

#### References and Collections:

This site is designed to be a resource for learning introductory level, algebra based, physics. Lessons and review are organized by topic. The collection features an especially robust section on Units, Measurement, Significant Figures, and use of measurement tools. A $5.00 annual fee gives teachers access to additional simulations, many of which have been rewritten to HTML5.

**Item Type:**Tutorial Collection

**Level:**High School Physics

This resource is a comprehensive guide on SI for teachers and students. It contains tables, charts, and text explanations of base units, derived units, equivalencies, common quantities, and prefixes. To aid the learner in visualizing quantities, drawings of common multiples are provided for each of the base units. The materials are written so that a user with no prior experience with metrics can comprehend the measurements and how they are applied mathematically.

**Item Type:**Reference Material

**Level:**Teacher Support

#### Content Support For Teachers:

This item, part of the Open Door website, discusses the role of uncertainty in measurement. Review the difference between systematic and random error, and gain practice in quantifying the error. Also find high-quality sections on the Vernier scale, "best-fit line", and sampling frequency.

**Item Type:**Online Tutorial

**Level:**Teacher Support

### Teaching Tools (3)

#### Activities:

This is a very easy to use digital tool for performing unit conversions with the extra feature of displaying cancellation of terms, helping students to gain a deeper understanding of the mathematical processes involved. Students can convert among 25 physical quantities, including units such as force, temperature, energy, and current.

**Item Type:**Mathematical Tool

**Level:**Grades 6-12

This free digital grapher is especially user-friendly for beginning learners. Students can choose from five graph types: bar, line, area, pie, and X/Y. Various patterns, colors, grids, and label choices are available to allow customization. Minimum and maximum values can be set to limit the scale of the graph.

**Item Type:**Graph-Making Tool

**Level:**Grades 4-12

#### Assessment:

Here is a set of free assessment tools for grades 6-12 on topics that cover force and motion, waves, properties of matter, and chemistry. *Diagnoser* assessments are aligned with the NGSS, and include elicitation (warm-ups) and developmental lessons. After completing the lesson, *Diagnoser* students answer digital question sets on specific topics, with immediate feedback provided to both teachers and learners. The final step in the process is "Prescriptive Activities", designed to target specific problematic areas located by *Diagnoser*.

**Item Type:**Assessment Tool

**Level:**Grades 6-12

### Dimensional Analysis (3)

#### Content Support For Teachers:

This web page is part of the highly-regarded *Hyperphysics* concept maps. It describes units of measurement, unit conversions, dimensional analysis, and basic mechanical quantities. Some of the maps are "active graphics", which link to capsules of background information. Remarkably easy to use!

**Item Type:**Reference Material

**Level:**Teacher Support

#### Student Tutorials:

Dimensions of a quantity refer to the combination of units or *base quantities* that make it up. Most physical quantities can be expressed in terms of five basic dimensions and their combinations: mass, length, time, electrical current, and temperature. Often, students have difficulty understanding why dimensions are different than units. This tutorial contains basic information, 3 short quizzes and one longer post-test. Your students can move at their own pace or work in cooperative groups. ***NOTE: This activity can be done without computers, as all components are printable.*

**Item Type:**Instructional Module

**Level:**Grades 9-12

**Duration:**2-3 class periods

Your students will need to understand how to cancel units before they can solve problems using dimensional analysis. Beginning with simple one-step conversions, it progresses to problems requiring multiple conversions. Students will like the informal writing style by the author, whose motto is "If I can do this stuff, then so can you!"

**Item Type:**Online Tutorial

**Level:**Grades 8-12

### Scale, Order of Magnitude, and Estimation (4)

#### Activities:

Students explore size estimation in 1, 2, and 3 dimensions. Multiple levels of difficulty allow for progressive skill improvement. Activity is great fun; expect students to be very engaged!

**Item Type:**Interactive Animation

**Level:**Grades 6-12

**Duration:**One class period

An updated version of "Powers of 10". View the Milky Way at 10 million light years from Earth, then move through space at successive orders of magnitude until you reach an oak tree in Florida. After than, move from a single leaf to the cell nucleus, chromatin, DNA, and subatomic particles.

**Item Type:**Image Set

**Level:**Grades 4-12

**Duration:**15 minutes

Interactively explore various specimens as they appear under a scanning electron microscope (SEM). SEM can produce very high-resolution photos of details as small as 1-5 nanometers. Students can adjust the focus, brightness, and contrast, and choose from a cockroach, pollen grain, diatom, a gecko foot, a jellyfish, and more. Each successive image doubles the magnitude of the magnification.

**Item Type:**Images/Illustrations

**Level:**Grades 5-12

**Duration:**30 minutes

This unique website compares the magnitude and size of a broad variety of objects, using colored histograms for ease of visual comparison. Objects range from the nanoscale to distances between galaxies. Most items are linked to annotated reference pages.

**Item Type:**Tutorial

**Level:**9-12

**Duration:**30 minutes

### Assessments (3)

#### References and Collections:

The National Assessment of Educational Progress (NAEP) is the only nationally administered, continuing assessment of what America's students know and can do in various subject areas. This website provides free access to the most recent assessment questions, organized by topic and level. Teachers can view an analysis of the results to see short-term and long-term trends in samples of students at ages 9, 13, or 17 years.

**Item Type:**Assessment Tool

**Level:**Grades K-12

#### Assessment:

This activity, authored by an AAPT Physics Teacher Resource Agent, helps students understand concepts of position and coordinates. Students must locate points on a graph paper using either components or distance and angle.

**Item Type:**Problem Set

**Level:**Grades 9-12

**Duration:**One class period

Here is a set of free assessment tools for grades 6-12 on topics that cover force and motion, waves, properties of matter, and chemistry. *Diagnoser* assessments are aligned with the NGSS, and include elicitation (warm-ups) and developmental lessons. After completing the lesson, *Diagnoser* students answer digital question sets on specific topics, with immediate feedback provided to both teachers and learners. The final step in the process is "Prescriptive Activities", designed to target specific problematic areas located by *Diagnoser*.

**Item Type:**Assessment Tool

**Level:**Grades 6-12