Waves Study Slides

1 Tally Questions

# 1 A “real life” example of a transverse wave is: My cat’s meow Food converting to energy My shirt is red A dog whistle being blown

# 1 Answer A “real life” example of a transverse wave is: My cat’s meow Food converting into energy My shirt is red A dog whistle being blown

# 2 A “real life” example of a longitudinal wave is: Gamma rays X-rays The Color Purple The bell at the end of class

# 2 Answer A “real life” example of a longitudinal wave is: Gamma rays X-rays The Color Purple The bell at the end of class

# 3 Pitch, a measure of a longitudinal wave, has to do with Amplitude Frequency Color Crests and Troughs

# 3 Answer Pitch, a measure of a longitudinal wave, has to do with Amplitude Frequency Color Crests and Troughs

# 4 Volume, a measure of a longitudinal wave, has to do with Amplitude Frequency Color Crests and Troughs

# 4 Answer Volume, a measure of a longitudinal wave, has to do with Amplitude Frequency Color Crests and Troughs

# 5 True or False: A Longitudinal wave needs a medium in order to travel. True False

# 5 Answer True or False: A Longitudinal wave needs a medium in order to travel. True –Sound is produced by the vibration of two particles/objects, etc.

#6 1 2 3 Describe the surface/object in which light is shining on in each picture.

#6 answer 1 2 3 Describe the surface/object in which light is shining on in each picture. 1- Opaque. No light is getting through. 2- Translucent. Some light is getting through. 3. Transparent. Light gets through easily.

#7 Why do our eyes see the color Red?

#7 Answer Why do our eyes see the color Red? As light is transmitted, it is either reflected or absorbed. If something is red, it is because all colors are absorbed, but red is the only color reflected.

2 Tally Questions

# 1 Define Wavelength: The thickness of a compression # of waves per second The distance between two crests or two troughs in a row How large a wave is

# 1 Answer Define Wavelength: The thickness of a compression (how you calculate amplitude of a longitudinal wave) # of waves per second (frequency of any wave) The distance between two crests or two troughs in a row How large a wave is (general definition of amplitude)

# 2 A Definition of Amplitude is: The measure from crest to trough # of waves per second The distance between two crests or two troughs in a row The measure of how large a wave is

# 2 Answer A Definition of Amplitude is: The measure from crest to trough (I made this up…this is not a measure) # of waves per second (Frequency of any type of wave) The distance between two crests or two troughs in a row (Wavelength of a transverse wave) The measure of how large a wave is

# 3 How do you measure the amplitude of a transverse wave? The distance from the line of origin to the crest or the line of origin to the trough. The distance from a compression to a rarefaction The # of waves per second The length from one crest to the next consecutive crest.

# 3 Answer How do you measure the amplitude of a transverse wave? The distance from the line of origin to the crest or the line of origin to the trough. The distance from a compression to a rarefaction The # of waves per second The length from one crest to the next consecutive crest.

# 4 The two pictures below show a change in Frequency Amplitude Color Wave speed

# 4 Answer The two pictures below show a change in Frequency Amplitude—Definition/intensity of compression Color Wave speed

# 5 The following shows a change in A. Amplitude B. Size C. Volume D. Wavelength

# 5 Answer The following shows a change in Amplitude Size Volume Wavelength **And frequency! (as one increases in wavelength, it decreases in frequency (and vice versa).

#6 The two pictures below show a change in WHAT? Describe. 1 2

#6 Answer The two pictures below show a change in Frequency/Pitch. Picture 1 has a lower frequency, so a lower pitch than Picture 2 1 2

#7 Contrast the speed of light and the speed of sound through different media. *Where does it travel fastest, slowest?

#7 Answer Contrast the speed of light and the speed of sound through different media. *Where does it travel fastest, slowest? Light Sound Light—the more matter the harder it is to travel. Sound—The more matter, the easier it is to pass along energy and vibrate. Fastest -----------------------------Slowest Vacuum, Gas, Liquid, Solid Solid, Liquid, Gas (doesn’t travel in a vacuum)

4 Tally Questions

# 1 Draw a picture of a longitudinal wave. Label a compression and a rarefaction. Label a wavelength.

# 1 Answer Draw a picture of a longitudinal wave. Label a compression and a rarefaction. Label a wavelength. Wavelength (Compression to Compression) ..Compression Rarefaction Amplitude (Thickness of Compression as the wave moves through the medium)

# 2 Draw a picture of a transverse wave. Label: A crest and a trough A wavelength The line of origin Amplitude in one spot

# 2 Answer Draw a picture of a transverse wave. Label: A crest and a trough A wavelength The line of origin Amplitude in one spot Crest AMPLITUDE (LINE OF ORGIN TO CREST) Wavelength (Crest to Crest) Trough Line of Origin AMPLITUDE (LINE OF ORGIN TO TROUGH)

# 3 Draw a picture of two transverse waves with a change in Amplitude. Include what an increase in Amplitude would mean for this type of wave in real life.

# 3 Answer Draw a picture of two transverse waves with a change in Amplitude SMALLER AMPLITUDE (SMALLER WAVE) LARGER AMPLITUDE (LARGER WAVE) (DIMMER LIGHT) (BRIGHTER LIGHT)

# 4 Explain what happens to Amplitude, Frequency, and wavelength the further you get away from a light source. Why?

# 4 Answer Explain what happens to Amplitude, Frequency, and wavelength the further you get away from a light source. Why? The source is the source of ENERGY. The further you get away from the source of energy, the less energy there is. Usually frequency and wavelength change is not noticeable (Doppler effect does not factor in here as that is just an EFFECT, it is not a true change in frequency). Amplitude, or size, decreases substantially. Therefore….light becomes dimmer, sound quieter.

# 5 The following picture shows a change in What? Yes, There is more than one answer here.

# 5 Answer The following picture shows a change in What? There is more than one answer here. # 5 Answer A B Picture A’s wavelengths are shorter than B. The waves in A are closer together, so the frequency is higher and therefore, so is the pitch. B’s waves are further apart, so frequency is lower (and so is the pitch).

# 6 There are 4 ways light can interact. What are they. Describe.

# 6 Answer There are 4 ways light can interact. What are they. Describe. Reflection---Light bounces back at the same angle it hits an object. *Mirrors/echo Refraction---Light bends due to entering an other medium (gas to liquid). Objects appear bent. Diffraction---Light spreads out around obstacles. *If light/sound CAN get out, it will. Interference---Constructive—Joins waves to become brighter. Destructive---Waves intersect and objects are harder to see.

5 Tally Questions FOR THE GROUP

# 1 Velocity (Speed) = Frequency x Wavelength Calculate the following: 1. A wave is traveling at 37.4 m/s. The Frequency is 15,000 Hz. What is the wavelength? Round to the thousandth. 2. 7 waves pass a fixed point every 12 sec. The waves have a length of 3.4 m. What is the speed of the wave? Round to the nearest 100th.

# 1 Answer 37.4 = .002 m 15,000 Speed = Frequency x Wavelength 1. A wave is traveling at 37.4 m/s. The Frequency is 15,000 Hz. What is the wavelength? Speed = Frequency x Wavelength 37.4 = 15,000 x ? 37.4 = .002 m 15,000 2. 7 waves pass a fixed point every 12 sec. The waves have a length of 3.4 m. What is the speed of the wave? Velocity (Speed) = Frequency x Wavelength ? =(7 waves per 12 sec) x 3.4 m ? = 7 x 3.4 12 1.98 m/s = .58 x 3.4

25 points for the GROUP Picture of water before a rock Picture of water after a Is thrown rock is thrown Explain what happened. Include Amplitude/Frequency, Energy types, AND wave types!

GROUP Answer “before” “after” There is very little energy in the water “before.” A rock, filled with Kinetic Mechanical Energy transfers its energy to the water. The energy flowing through the water is still mechanical. Around where the rock hit (the source of energy), the amplitude is high (large waves) and the frequency is high (waves close together). As the energy travels through the water in TRANSVERSE (up and down) waves away from the source, the energy is transferred through all surrounding water and it begins to decrease, thus decreasing in size (amplitude). Frequency SHOULD remain the same, but if objects or substances interfere (changing the density of the medium), or the energy transfers to a different medium, that affects the speed of the wave (which affects the frequency).