Labs for Ray Optics

We have a collection of ~150 labs in the Laboratory section of the website. Each lab was intended to be used with a lab notebook where students report their data and findings and state their conclusion with supporting evidence and reasoning. The intent was to provide a relatively clear purpose (or question) to students that they would need to address AND to limit the amount of directions. The hope is that the purposes and students' ability to design a procedure would drive the lab activity (in contrast to a detailed set of step-by-step procedures being the driving force of students' activity). As such, each of our labs comes with a Question and Purpose and a short paragraph describing what should be included in students' lab report. On occassion, students are also provided a graphic organizer, data table, or other item to be taped into their notebook. The following pages may be useful for those teachers who wish to adopt or simply trial our Labs with a Purpose approach:

Our Thoughts on the Approach || About Lab Notebooks || Teacher Guides for All Labs

Lab 1 - The Law of Reflection Lab

Question:
What general principle could be stated to describe how light reflects off a plane mirror surface?

Purpose:
To determine a general principle which describes the manner in which light reflects off a plane mirror surface.

A complete lab write-up includes a Title, a Purpose, a Data section (with provided graphic and several labeled laser light paths), a Conclusion and a Discussion of Results. The Conclusion should include a generalized statement expressed in your own words which describes how light reflects off a mirror. The Discussion of Results should describe how the findings reported in the Data section logically lead to the conclusion which you have made. Specific trials that justify your conclusion should be identified.

View: Teacher's Guide

Lab 2 - Plane Mirror Image Lab

Question:
How is an image formed by a plane mirror and what are some characteristics of such images?

Purpose:
To describe the manner by which a plane mirror produces an image of an object and to describe the characteristics of such images.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion/Discussion. The Data section should include a diagram with a mirror line (labeled), an object (tea light candle), an image, and four sets of incident and reflected rays originating from the object (two sets on each side of the mirror), extensions of reflected rays to show image location, and clearly labeled measurements of object and image distances. The Conclusion/Discussion should respond to the question raised in the Purpose of the lab (as always). 

View: Teacher's Guide
(None available; actual labs will be included in Course Package)

A pandemic era video of this lab can be found here.

Lab 3 - The Six Foot Person Problem

Question:
How does the amount of mirror required to view an image of yourself compare to your height? Does the distance from the mirror affect your answer?

Purpose:
To use laser light in order to compare the portion of a mirror required for a person to view him/herself to the height of the person.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion and a Discussion of Results. The Data section should include the provided diagram with laser-guided incident and reflected rays showing the path of light from the head and toe to the eye for two different object locations; measurements should be clearly made and labeled on the diagrams. Class data should be included in the Data section. The Discussion of Results should include a discussion of how the collected data lead logically to the stated conclusion. The Discussion section should also include an error analysis comparing the experimental results to the expected results; a percent error analysis might be included.

View: Teacher's Guide || Data Table

Lab 4 - Exploring Curved Mirrors

Question:
How does the orientation and relative size of an image change as the object is moved from a position close to a concave mirror (and a convex mirror) to a position very far away?

Purpose:
To describe the changes in the relative image size and image orientation which are observed as a person moves from a position very close to a curved mirror (both concave and convex) to a position very far away.

A complete lab write-up includes a Title, a Purpose, a Data section (with organized observations for the two types of mirrors), and a Conclusion/Discussion. The Conclusion/Discussion section should include a discussion of the manner in which the relative image size and orientation change as the object moves from a nearby position to a distant position. The discussion should include both types of curved mirrors.

View: Teacher's Guide

Lab 5 - Finding Smiley

Question:
Under what conditions will an object placed in front of a concave mirror produce a magnified-in-size image, a reduced-in-size image, an upright image, and an inverted image.

Purpose:
To describe the conditions that are required for producing a magnified-in-size image, a reduced-in-size image, an upright image, and an inverted image for a concave mirror.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion/Discussion. The Data section should include a table with column headings "Smiley Location", "Image Location", "Relative Image Size", and "Orientation". Trials should be conducted for Smiley Locations of at C, further from mirror than C, between C and F, and closer to mirror than F. The Conclusion/Discussion should respond to the question raised in the Purpose of the lab (as always). 

View: Teacher's Guide
(None available; actual labs will be included in Course Package)

Lab 6 - Introduction to Refraction

Question:
What is refraction? Why does refraction occur? When does refraction occur? How does refraction occur? And when does refraction not occur?

Purpose:
To understand the what, why, when, how, and when not of light refraction.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion /Discussion section. The Data section should include a diagram of a prism and rays depicting the path of laser light towards, into, through, out of, and away from a glass prism. Normal lines should be constructed and labeled for each boundary. The Conclusion/Discussion section should respond to the five parts of the purpose, providing an answer to each of the five questions. For each answer, evidence and/or examples from the Data section should be cited in support of the answer.

View: Teacher's Guide
(None available; actual labs will be included in Course Package)

Lab 7 - How Much?

Question:
What is the mathematical equation relating the angle in air to the angle in water for light refracting across the boundary from air into water?

Purpose:
To state the experimentally-derived equation relating the angle in air to the angle in water for light refracting across the boundary between air and water.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion and a Discussion of Results. The Data section should include a table of data with column headings and units, a graph of sinθ_air vs. sinθ_water. Linear regression should be performed for the graph and the slope, y-intercept, regression constant and equation should be reported. Class data for the slope of the line should be recorded and subsequently used in your Discussion of Results. The Conclusion should respond to the question raised in the Purpose of the lab (as always). The Discussion of Results section should include an error analysis in which you evaluate the reliability of your data and of your equation. An error analysis should always respond to the question how well did we do? and provide evidence for the answer. In this lab, an error analysis should include a comparison of the experimentally-derived equation with the equation which would be expected based upon textbook reading.

View: Teacher's Guide

Lab 8 - Determining n

Question:
What is the index of refraction for the materials which comprise a variety of prisms?

Purpose:
To determine the index of refraction of the unknown materials which comprise a variety of prisms.

A complete lab write-up includes a Title, a Purpose, a Data section and a Conclusion. The Data section should include an outline of at least two of the provided prisms; the path of the laser light into, through and out of the prism should be indicated by light rays. Proper constructions and measured angles should be included on each diagram in an effort to determine the index of refraction of the material of the prism. Measurements and calculations should be made (and clearly shown) for the entry and the exit boundary; an average nvalue for each prism should be reported. The Conclusion should respond to the question raised in the Purpose of the lab (as always).

View: Teacher's Guide

Lab 9 - A Critical Lab

Question:
At what angle does refraction cease to occur in such a manner that light undergoes total internal reflection?

Purpose:
To determine the critical angle for the water-air boundary and for the Lucite-air boundary.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion and a Discussion of Results. The Data section should include two diagrams - one for each boundary. The diagram should display a light ray approaching the boundary at the critical angle and the refracted ray at the appropriate angle. Critical angles should be recorded. The Conclusion should respond to the question raised in the Purpose. The Discussion of Results section should include a short error analysis and include percent error calculations for the two critical angle values.

View: Teacher's Guide

Lab 10 - Exploring Lenses Lab

Question:
How would you describe the images formed by a converging and a diverging lens for nearby and distant objects?

Purpose:
To describe the orientation and relative size of the images produced by a converging and a diverging lens for nearby and distant object locations.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion/Discussion. The Data section should document the observations of relative size and orientation in an organized manner; a table would be a wonderful idea. The Conclusion/Discussion should include an organized paragraph in which you respond to the question raised in the Purpose of the lab.

View: Teacher's Guide

Lab 11 - The L•O•S•T Art of Image Description

Question:
How do the characteristics of images formed by converging lenses compare for various object locations?

Purpose:
To describe the relative location, orientation, size and type of the image produced of an object by a converging lens when the object is located at four strategic locations along the principal axis.

A complete lab write-up includes a Title, a Purpose, a Data section, a Conclusion/Discussion. The Data section should include a table in which you identify the observed (LOST) characteristics of the images for object positions beyond the 2F location, at the 2F location, between the F and 2F locations and inside F. The data table should be accompanied by a diagram depicting the strategic locations. The Conclusion/Discussion should include an organized paragraph in which you respond to the question raised in the Purpose of the lab.

View: Teacher's Guide || Data Table

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