After our waves experiments, fourth graders quickly realized that waves can travel at different speeds and that the sizes of waves can be very different. Waves can be big, yet travel slowly. They can be big, but move quickly.
This led us into seeing that there are specific parts to each wave we see and that identifying these parts can help us measure waves.
Crest: The top of a wave
Trough: The bottom of a wave
Midpoint: The middle of a wave (in between the crest and the trough)
Wavelength: How long a wave is from two identical parts (crest to crest, midpoint to midpoint, or trough to trough)
Amplitude: How high (or deep) a wave is.
We can specifically measure the wavelength of a wave by counting the number of units a wave is from crest to crest (or midpoint to midpoint, or trough to trough). We can specifically measure the amplitude of a wave by counting from the baseline (the imaginary line that runs through the midpoints) up to the crest or down to the trough. Waves can have the same amplitudes but different wavelengths. Simultaneously, they can have the same wavelengths but different amplitudes!
This led us into seeing that there are specific parts to each wave we see and that identifying these parts can help us measure waves.
Crest: The top of a wave
Trough: The bottom of a wave
Midpoint: The middle of a wave (in between the crest and the trough)
Wavelength: How long a wave is from two identical parts (crest to crest, midpoint to midpoint, or trough to trough)
Amplitude: How high (or deep) a wave is.
We can specifically measure the wavelength of a wave by counting the number of units a wave is from crest to crest (or midpoint to midpoint, or trough to trough). We can specifically measure the amplitude of a wave by counting from the baseline (the imaginary line that runs through the midpoints) up to the crest or down to the trough. Waves can have the same amplitudes but different wavelengths. Simultaneously, they can have the same wavelengths but different amplitudes!