Waves

Activity 14: Blocking Out Ultraviolet

Students design an experiment that compares the effects of sunscreen lotion and moisturizing lotion for their abilities to transmit, reflect, or absorb ultraviolet. Then students relate the results to the sun’s effects on human health and actual use of sunscreens. Students apply the concepts of transmission, reflection, and absorption of ultraviolet while planning and carrying out an investigation. They use models to compare the effectiveness of sunscreen and moisturizing lotion in blocking ultraviolet. Students are given the opportunity to apply their findings from this investigation to previous activities as they discuss how structure and function influence the effectiveness of sunglasses in comparison to sunscreens.

Activity 13: Where Does the Light Go?

In this activity, students compare the reflection and absorption of sunlight off a dark surface and a reflective surface. They gather evidence to determine whether non visible electromagnetic waves can be selectively reflected and absorbed. Then they consider the increased health risks from sunlight that is reflected onto the skin and eyes from sand, snow, and water. Students analyze and interpret patterns in their data and then use the model in the activity to explain how structures can be designed to minimize or maximize reflection or absorption. 

Waves 11: Selective Transmission

Students build on the concepts previously presented by investigating light beyond the visible spectrum. Students conduct an investigation to test how different films affect the transmission and absorption of light. As they analyze and interpret the data they have collected, they learn that there are invisible waves at both ends of the visible spectrum and that these waves, like visible light, transfer energy when absorbed. Students select and justify which structural films would be most functional to use on windows in three different situations. 

Waves 10: Comparing Colors

In Activity 10, students first observe that visible light can be separated into different colors. Students then conduct an investigation to collect evidence that indicates that different colors of light carry different amounts of energy. In their final analysis, students analyze and interpret light transmission graphs for three different sunglass lenses. They determine which sunglass lens (structure) provides the best protection (function) for the eyes.

Activity 9: Refraction of Light

In this activity, the students experiment with the transmission of light rays by planning and carrying out an investigation of the refraction of light through water.  Looking for patterns in their data, students search for a qualitative relationship between the angle of incidence, angle of refraction, and index of refraction. Students plan and carry out an investigation that determines the critical angle for total internal reflection. Students identify the crosscutting concept of structure and function as they apply their understanding of total internal reflection as it is used in fiber optics.

Activity 8: Wave Reflection

In this activity, students investigate the reflection of sound and light waves. They find that some surfaces are good reflectors of sound, whereas others are good absorbers of sound. These characteristics are applied to acoustic design in an application of the crosscutting concept of structure and function. Building on their observations of the relationship between the direction of incident and reflected sound waves, students analyze collected data and deduce the law of reflection as applied to light waves. They model the law as they create ray diagrams to represent both regular and diffuse reflection.

Activity 7: Another Kind of Wave

We experience many different types of waves (sound, light, water, seismic, etc.) Students apply what they learned about longitudinal waves in a previous activity to transverse waves in a long metal spring. Using a long metal spring, students investigate transverse waves. They investigate such properties of the waves as wavelength and amplitude. They use a model to identify patterns to deduce the inverse relationship between frequency and wavelength, and the direct relationship between amplitude and energy. Students perform calculations and make conceptual connections to make an explanation of the relationships found. As students move forward in the unit, these discoveries give them a foundation in transverse waves that allows them to fully explore phenomena involving light. 

Activity 5: Telephone Model

This activity introduces students to digital and analog sound transmission. First, they investigate how sound is transmitted through a model telephone, and then they model how noise interference affects the received signal. Students model how noise interference affects the transmission and reception of analog and digital signals. They find that the structure of digitized signals, sent as wave pulses, function as a more reliable way to encode and transmit information. They examine the structure and function of the model used in the activity.

Activity 4: Noise-Induced Hearing Loss

In this two part activity, students use mathematics and computational thinking as they analyze and interpret data related to the risk of noise-induced hearing loss. In doing so, students plot a line graph and determine the relationship between relative intensity of sound and the maximum allowed exposure time. They use the graph to estimate a safe time for exposure to a certain level of sound. Students read the profiles of several individuals and use the information obtained to evaluate and communicate the risk of noise-induced hearing loss for each one. Students then examine the structure and function of the protection provided by two kinds of ear protection.

Activity 2: Making Sound Waves

The activity begins with students using a variety of devices including whirly sound tubes to make sounds. They look for patterns in how they can make the devices produce louder or softer, and higher and lower pitch sounds. Students are then introduced to a diagrammatic model of a sound wave traveling through air. They use a metal spring to create a dynamic model of sound. After exploring the terms intensity and frequency, students adjust their spring models to represent changes in these two variables.

Waves 1: It's a Noisy World

To kick off the Waves unit, students brainstormed questions to add to our Driving Question Board. They thought about the Anchoring Phenomena, that waves can be helpful and harmful,  then generated questions.  After sharing out their questions, they wrote the question they most want to answer on a sticky note. We then looked at the four driving question for the Waves Unit, and placed their questions near the driving question closest to their own. 

1. How much sound energy is safe?

2. How can wave technology be used to enhance or protect human senses?

3. How do different types of waves transfer energy?

4. How can exposure to sunlight harm humans?

Students will be asking new questions and adding to the DQB as they learn more. Then, in the first activity in the Waves Unit, students examined cards that represent the relative intensity of various sounds. They learned about the decibel scale as a measure of sound intensity, and that an increase of 10 dB is equivalent to a tenfold increase in sound intensity. They then applied what they learned to relate sound intensity to risk of hearing loss.