# Light & Color

Arbor Scientific is providing physics and physical science teachers with a collection of student lab activities the study of Light and Color. Here you can browse lab activities by topic and get teachers notes, student worksheets and a list of equipment and supplies needed for each activity.

## Refraction: Converging Lenses

Students investigate images formed by converging lenses using the Light Box & Optical Set, and discover the Focal Point.

Required Equipment
Light Box and Optical Set, Power Supply

## Light Box and Optical Set

In Stock SKU: P2-9561
\$139.00

## Light Box Power Supply

In Stock SKU: P4-7250
\$69.00

## Index of Refraction

The semicircular block is ideal for a first quantitative activity on refraction. When placed as in this activity, rays bend only when exiting the block, simplifying observations. Students will measure angles of incidence and refraction, and calculate the index of refraction of Plexiglas.

Required Equipment
Light Box and Optical Set, Power Supply, Protractor, Refraction Cup

## Light Box and Optical Set

In Stock SKU: P2-9561
\$139.00

## Light Box Power Supply

In Stock SKU: P4-7250
\$69.00

## Protractor

In Stock SKU: P1-1050
\$1.30

SKU: P2-1230
\$2.75

## Law of Reflection of Light Pt. II

Observe objects through a periscope. Draw ray diagrams to explain image formation. Extend the activity by rotating one of the periscope mirrors and explaining the resulting inverted image.

Required Equipment
Periscope

## Periscope

In Stock SKU: P2-7080
\$26.00

## Reflection and Refraction

The Law of Reflection states that the angle of incidence is equal to the angle of reflection. Students will use ray tracing to predict the location and image characteristics for flat and curved mirrors. Students will use ray tracing to discover and explain how different types of images are created with plane, concave and convex mirrors

Required Equipment
Laser Ray Box and Optical Set, Mega Mirrors, diagram sheets.

Acknowledgements: Thank you to Lori Anderson for developing this lab. Lori is a veteran physics teacher at Grafton High School, in Virginia.

## Laser Ray Box and Lenses

In Stock SKU: P2-7680
\$99.95

## Pair of Mega Mirrors

In Stock SKU: P2-7150
\$299.00

## Images Produced by Curved Mirrors

Students use the Light Box and Optical Set’s two different curved mirrors to investigate how light reflects from concave mirrors. Students make predictions and observations, and make generalizations about the focal point of a mirror, depending on its curvature.

Required Equipment
Light Box and Optical Set, Power Supply

## Light Box and Optical Set

In Stock SKU: P2-9561
\$139.00

## Light Box Power Supply

In Stock SKU: P4-7250
\$69.00

### Seeing isn’t just believing… it’s learning!

“Think red and green make brown? Only with paint and crayons! In color science, those colors of light make yellow. When I demonstrate that with the Color Mixing Spotlights, students discover there’s no one answer for what color a strawberry is. The demo doesn’t just give them a new way of seeing color, it shows them science as a new way of seeing their world.”

Buzz Putnam is an award-winning physics teacher and Science Department Chair at Whitesboro High School in New York. Buzz also conducts Teaching Methods classes for science teachers at Utica College of Syracuse University. In addition, he is part of the Cornell University Laboratory Development Team and a member of the Cornell NanoScale Institute for Physics Teachers.

### See the World In a Whole New Light!

With Color Addition Spotlights, three seemingly simple questions give students startling answers — and all-new interest in the science of light!

What Color Is A Strawberry?
Explain that it looks red because red light is available and red light reflects back to our eyes. To confirm, shine all three spotlights on the strawberry. Then, shine only the green spotlight on the strawberry: it will appear black.

If A Strawberry Can Appear Black, What Color Is A Shadow?
Hold your hand in front of the red spotlight: your shadow is black and the background red. Add the green spotlight. The red and green lights mix and the background becomes yellow creating two shadows of green and red!

Why Is The Sky Blue?
Using the Color Addition Spotlights, by mixing the red, green and blue light circles, you will create white light. So why is the sky blue and our Sun yellow? When the white light from our Sun strikes the Earth, blue light is scattered by our atmosphere more than the other colors of the spectrum. When that happens (turn off the blue spotlight), red and green light remain and that’s what produces a yellow-looking sun!

Required Equipment

Recommended quantity per classroom: 1

P2-9700

Our new Color Addition Spotlights give you three distinct circles of colored light which can be overlapped in any combination, showing color addition, complementary colors, color fatigue, and colored shadows.

Includes three spotlights w/ power supplies.

Recommended quantity per classroom: 1

Control Box for Spotlights
P2-9703

The optional Control Box has three sliding dimmer switches that allow you to adjust the brightness of each color. You can compensate for bulb inconsistencies or create “recipes” for any color in the spectrum!

## The Fiber Optics Principle

Students discover that magic is really science… Students got so fascinated with air to water refraction that they raced ahead to explore other possibilities. One group called me over when they found that when the laser beam hit the water to air boundary at a certain angle, it got trapped. They had discovered the secret of Total Internal Reflection and fiber optics for themselves!

Dean Baird has taught high school physics since 1986, leads workshops for new teachers, and is the author of lab manuals for Conceptual Physics, Conceptual Physical Science and Conceptual Integrated Science.

### The Fiber Optics Principle

1. Ask students to shine a laser from the air into the water at various angles and record the respective angles of refraction.

2. Shine the laser through the water and up into the air. Test and record the refraction at angles up to 40 degrees.

3. Then, ask them to predict what will happen when the laser is shown up through the water at 50 degrees.

4. When the angle is increased to 50 degrees or greater, the light doesn’t exit the water. Students discover Total Internal Reflection — how optical fibers work.

Required Equipment
Green Laser and Laser Viewing Tank

Recommended quantity per classroom: 1

Deluxe Green Laser Pointer
P2-7675

With a range of 2 miles the Deluxe Green Laser Pointer has the highest output power allowed by the FDA! 532 nm green laser pointer includes two AAA batteries.

Recommended quantity per classroom: 1

Laser Viewing Tank
P2-7690

Teacher-designed for student exploration of light beams! This versatile system allows students to see and control light beams.

 Color Addition Students use the Light Box and Optical Set to observe the results of combining beams of colored light. Concepts include primary and secondary color addition and complementary colors. Required Equipment Light Box & Optical Set Acknowledgements: Thank you to Dale Freeland for his work in developing this lab. Dale is an award-winning physics teacher and co-author of our Light & Color Teachers Guide. You may also have seen him present physics related workshops at NSTA conferences and State science conferences around the country. Download Teacher Notes and Student Worksheets

## Light Box and Optical Set Group

In Stock SKU: light-box-optical-set_group
\$49.00

## Reflection & Refraction

One day in my classroom…“My students were amazed by examples of colorful fiber optics but didn’t understand how the light goes from one end to the other; even when bent. After testing various angles of laser light through water and air up to 40 degrees, most students assume the light will continue to exit the other side. When the angle is increased to 50 degrees or greater, the light ray doesn’t come out the other side. Students finally see how fiber optics work through the phenomenon of Total Internal Reflection and have a great time exploring with this easy to set up lab!”Lori Andersen is a Physics and AP Physics teacher at Grafton High School in York County, VA.

Can a Trapezoid Trap Light?

Purpose: To discover the conditions that result in total internal reflection in a transparent material.

Summary: Students use the Laser Ray Box and trapezoidal lucite block to find situations that result in total internal reflection.

Question: How can a transparent medium be used to reflect light?

Materials: Laser Ray Box, trapezoidal block, graph paper, pencil, ruler, protractor.

Process: Ask students to predict what will happen if the laser light is directed toward the trapezoid along the normal to each side. Have each lab group sketch the predicted path of the laser beams.

Students trace the outline of the trapezoid on the graph paper. Use the protractor to draw a normal for each side of the trapezoid. Students point the laser along the normal. Trace the path of the rays (approaching the trapezoid, inside the trapezoid, and leaving the trapezoid) with a pencil and ruler. For each ray, use the protractor to measure and label the angles of incidence and refraction (or reflection) on the graph paper.

Did the observations agree with predictions? Encourage students to explain the differences between their predictions and their observations. Challenge students to find the critical angle for the lucite.

Results: Students will notice that for the angled sides, total internal reflection is observed when the laser light reaches the bottom side. This does not occur for the parallel sides.

Discussion: When light goes from lucite to air at an angle greater than the critical angle, there is no refracted ray, and all the light reflects back into the lucite! Show students using Snell’s Law why this occurs. Introduce examples of fiber optics applications that utilize this phenomenon, such as laparoscopic surgery and fiber optic communications.

Required Equipment
Laser Ray Box, trapezoidal block, graph paper, pencil, ruler, protractor.

Recommended quantity per lab group: 1

## Laser Ray Box and Lenses

In Stock SKU: P2-7680
\$99.95