Waves

Learning Scale … I can 4 – Design an experiment to show how waves move at different speeds through different materials. 3 – Explain why waves move at different speeds through different materials. 2 – Recall the terms: crest, trough, amplitude, wavelength, & frequency 1 - Identify types of waves.

Transverse Wave The crest = highest point on a transverse wave The trough = lowest point on a transverse wave

The wavelength is the distance from one point on the wave to the next corresponding adjacent point.

Compressional Wave Compression = Tightly coiled section Refraction = Loose, less coiled section

Wavelength vs. Frequency The distance from one point on the wave to the next corresponding adjacent point As you increase one, you decrease the other. Frequency is the number of waves that pass through a point in one second.

What is the amplitude of a wave? Transverse Wave Height of crest or trough from standstill Larger the height, greater the energy Compressional Wave Greater amplitude = Tighter coils Less amplitude = Loose coils

1. How does the frequency of a wave relate to its wavelength? 2. Name two types of waves. 3. Name two parts of each wave. 4. How is amplitude of a longitudinal wave measured? KNOWLEDGE CHECK

1. How does the frequency of a wave relate to its wavelength? The greater the frequency, the smaller the wavelength. 2. Name two types of waves? Longitudinal and Transverse 3. Name two parts of each wave. Longitudinal = Compression/Rarefaction Transverse = Crest/trough 4. How is amplitude of a longitudinal wave measured? Based on the tightness of the coils KNOWLEDGE CHECK

We see things because they reflect light into our eyes: Homework

Reflection A bouncing back of a wave after it hits a barrier Does not go through a barrier Echo = reflection of a sound wave Incident ray Reflected ray Mirror

REFRACTION Bend a wave at an angle as it hits a medium/barrier Light waves -> Prism -> Rainbow Light (colors) have a different wavelength; a prism breaks them apart.

Sound Waves & Speed Sound travels different speeds through different mediums. The denser the medium, the faster sound will travel (Fastest = solid, medium = liquid, slow = gas) The higher the temperature of a gas, the faster the particles of the medium will move and the faster the particles will carry the sound. The lower the temperature of a solid/liquid, the closer the particles of the medium and the faster the particles will carry the sound.

Write this next part down! Title: Sound Waves

What is sound intensity? Sound intensity is the energy that the sound wave possesses. The greater the intensity of sound the farther the sound will travel and the louder the sound will appear. Loudness is very closely related to intensity. Loudness is the human perception of the sound intensity. The unit for loudness is decibels.

How is frequency related to pitch? The pitch of a sound wave is directly related to frequency. A high-pitched sound has a high frequency. ex. screaming girl A low-pitched sound has a low frequency. ex. fog-horn A healthy human ear can hear frequencies in the range of 20 Hz to 20,000 Hz. Humans cannot hear below 20 Hz. Sounds below this frequency are termed infrasonic. Sounds above 20,000 Hz are termed ultrasonic.

Loudness in Decibels

1. What type of matter does sound travel best through? 2. How does temperature affect the speed of sound? 3. What is the relationship between pitch and frequency? KNOWLEDGE CHECK

1. What type of matter does sound travel best through? Solids 2. How does temperature affect the speed of sound? The higher the temperature, the faster the sound will travel. 3. What is the relationship between pitch and frequency? Pitch and frequency are directly related. KNOWLEDGE CHECK