Making Waves

This unit introduces basic properties of waves and helps students learn to distinguish between the many types of waves they encounter daily. Students explore how the energy of a mechanical wave can travel through a medium.

Activities

Scene: Surf's Up (and Down, and Up Again)

Shani, Journey, and Luisa consider the nature of different kinds of waves as they watch their friend Kenzo surf.

Duration: Approximately 50 minutes

Interactive: A Wave with Words

Students go deeper into the meaning of different wave-related terms in this interactive, animated guide.

Duration: Approximately 55 minutes

Lesson: Modeling Mechanical Waves

Students explore the nature of waves using several interactive and animated models.

Duration: Approximately 115 minutes

Demo: Ripple Tank

Build a ripple tank for students to explore the properties of waves, use a wave simulator, and look for examples of wave reflection, interference, and refraction around the globe.

Duration: Approximately 70 minutes plus 30-minute exploratory extension

Lab: Sound Stations

Students deepen their understanding of waves through a series of quick experiments focused on the mechanical nature of sound. Students use a special combination keyboard and oscilloscope to examine the nature of waves.

Duration: Approximately 50 or more minutes

Conversation: Waves of Danger

Students use their knowledge about waves to interpret geological data, and then explore what makes some earthquakes (and their accompanying tsunamis) deadlier than others. They brainstorm how best to spend an earthquake preparedness budget.

Duration: Approximately 80 minutes

Student View of Visuals and Activities

Some teachers prefer to have students view the slides and other visual assets in this unit directly instead of projecting them in class. Below is a web page to share with students with links to some of same items that are within in the teacher lesson plans, but without the explanatory text for the teacher.

 

• Student Links to Unit E4 Slides and Other Visuals

Teacher Tune-ups

• What types of waves are there, and what do they have in common?
• How can energy travel when matter doesn’t?

wave

noun – a moving disturbance

Let's just stay put and wait for this wave to go by.

frequency

noun – the rate at which something repeats over time

I go to this beach with some frequency, because the waves also come with great frequency. More waves, more surfing!

amplitude

noun – measurement of highest point (or lowest point) in a wave when compared to its resting position

The amplitude of a wave increases with more energy.

trough

noun – the area around the lowest point of a wave; sometimes called a “valley”

While waiting for a wave to surf, it can be very relaxing to rise with each passing crest and slide into each passing trough.

crest

noun – the top of something; the area around the highest point of a wave; sometimes called a "peak"

Surfers stay a little ahead of the crest of a wave and slide down the front of it.

wavelength

noun – the distance in a wave between one crest and the next, or between two consecutive troughs

Waves with high frequencies also have shorter wavelengths.

compression

noun – the state of being squeezed or pressed together

Sound waves are compression waves. When we clap our hands, the air between our hands gets compressed. The air molecules bump into each other, creating a vibration that travels through the air as a longitudinal or compression wave.

medium

noun – a substance (like a solid, liquid, or gas) that the energy of a wave can travel through. In the example above, the medium is a flag.

All mechanical waves need a medium—such as water, air, or metal—to travel.

vibrate

verb — to move back and forth (or up and down) around a point; to shake with small, rapid movements to and fro.

Instruments make sounds when some parts of them vibrate, which moves the air molecules inside or around the instrument.

period

noun – a length of time

The period of one wave is the time it takes two crests to pass a point.

diffraction

noun – bending or turning of a wave around obstacles, or spreading out after the waves pass through small openings

Wave fronts bend as they go through a narrow opening, demonstrating diffraction.

refraction

noun – bending or turning of a wave as it goes from one medium to another, for example a light wave bending from air to water

Wave fronts bend as they approach a beach, demonstrating refraction.