8th Grade Science 09/24/2014 Essential Question - How does a wave
transfer energy? Objectives - I can...
Describe the relationship between the frequency and wavelength of a wave
Explain why waves travel at different speeds.
Bell Ringer - Copy and answer the following question on your bell ringer sheet.
How are mechanical waves and electromagnetic waves different? How are they alike?
Waves Review
A wave is a traveling disturbance that carries energy from one place to another.
Energy is the ability to do work or cause a change
Amplitude Amplitude - is
measured from the equilibrium position to the top of a crest or the bottom of a trough.
The amplitude of a transverse wave is a measure of how high the crests are or how deep the troughs are.
Wavelength Another way to describe a wave
is by its wavelength. The highest points of waves
are called crests. The lowest points of waves are
called troughs. A wavelength, for a
transverse wave, is the distance from one crest to the next.
A wavelength, for a compressional wave, is the distance between the center of one compression and the center of the next compression.
Wavelength Visible light is only a small
part of the electromagnetic spectrum.
It is the wavelength of visible light waves that determines their color.
For example – The wavelength of red
light waves is longer than the wavelength of green light waves.
Frequency Frequency is number
of complete wavelengths in a given point.
As a wave length increases in size, its frequency and energy decrease.
8th Grade Science 09/24/2014 Essential Question - How does a wave transfer
energy? Objectives - I can...
Describe the relationship between the frequency and wavelength of a wave
Explain why waves travel at different speeds. Bell Ringer - Copy and answer the following
question on your bell ringer sheet. How does increasing energy affect the
frequency and wave length of a wave?(hint – Think about the turtle and Rabbit picture)
Frequency and Energy As a wave length
increases in size, its frequency and energy decrease.
As a wavelength decreases in size, its frequency and energy increase.
Agenda
1. Review wavelength, amplitude, and frequency.
2. Notes on speed of waves
3. Begin Wave worksheet
4. Correct quizzes and complete reflection sheet
Review Amplitude – the
measurement from the top of the crest, or bottom of the trough, to the middle (equilibrium)
Wavelength – The length of a single wave cycle
Frequency – the number of waves that pass a given point in a given amount of time.
Speed of Waves To calculate the speed of the wave, use the
formula:
Wave speed = Wavelength X frequency
10 cm
10 cm