Waves Test Review
1 (P.7A) As a transverse wave travels through a medium, the individual particles of the medium move______
Perpendicular to the direction of wave. Remember the first letter “T” of transverse. It looks like two lines meet Perpendicular to each other.
2 (P.7A, P.3F) The diagram below represents a transverse wave traveling to the right through a medium. Point A represents a particle of the medium. In which direction will particle A move in the next instant of time?______
Be sure that the medium particle does not move along with waves, but it oscillates up and down only. In the next instance, a trough of the wave comes to the point A of the medium. Then the medium of point A moves down.
3. (P.7A, P.2J) The diagram below represents a vibrating string with a periodic wave originating at A and moving to G, a distance of 6.0 meters. As the wave moves toward G, point E on the string will move ______
Be sure that the medium particle does not move along with waves, but it oscillates up and down only. In the next instance, a trough of the wave comes to the point E of the medium. Then the medium of point E moves down.
4. (P.7A) The diagram below shows a transverse water wave moving in the direction shown by the velocity vector v. At the instant shown, a cork at point P on the water's surface is moving toward
/ ______Be sure that the medium particle does not move along with waves, but it oscillates up and down only. In the next instance, a crest of the wave comes to the point P of the medium. Then the medium of point P moves up.
5. (P.7A) As shown in the diagram below, a transverse wave is moving along a rope. In which direction will segment X move as the wave passes through it? ______
Be sure that the medium particle does not move along with waves, but it oscillates up and down only. In the next instance, a crest of the wave comes to the point X of the medium and followed by a trough. Then the medium of point X moves up and then down.
6. (P.7A) A wave is generated in a rope which is represented by the solid line in the diagram below. As the wave moves to the right, point P on the rope is moving toward which position? ______
Be sure that the medium particle does not move along with waves, but it oscillates up and down only. In the next instance, a trough of the wave comes to the point P of the medium. Then the medium of point P moves down to C.
11 P.7B) A longitudinal wave moves to the right through a uniform medium, as shown below. Points A, B, C, D, and E represent the positions of particles of the medium. Indicate the wavelength of the given wave in the diagram.
In the longitudinal wave, a compression corresponds to a crest of a sine curve and a rarefaction to a trough of a sine curve. Wavelength is the distance from crest to crest or trough to trough or of two identical points of waves. Then AC represents exactly two identical points of two waves.
12 (P.7B, P.2J) The distance between which two points on the diagram below identifies the amplitude of the wave? ______
/ Amplitude is the maximum displacement from the equilibrium position. Answer is DA or AE.13 (P.7B) If the amplitude of a wave traveling in a rope is doubled, the speed of the wave in the rope will ______
Remember that speed is the product of wavelength and frequency. Speed is not affected by change in amplitude. So it remains constant.
14 (P.7B) Increasing the amplitude of a sound wave produces a sound with______
Amplitude represents the loudness of sound. As the amplitude increases, so the sound gets louder.15 (P.7B) A periodic wave is produced by a vibrating tuning fork. The amplitude of the wave would be greater if the tuning fork were ______
You can make a bigger sound of a tuning fork by striking it harder.
16 (P.7B) The wavelength of the wave in the diagram below is equal to the distance between points ______
What is the definition of a wavelength?
17 (P.7B, P.3F) What is the wavelength of a periodic wave having a frequency of 5.0 Hz and a speed of 10. m/s? ______
Speed equals product of wavelength and frequency. Then wavelength is 2.0 m.18 (P.7B) If the amplitude of a wave is increased, the frequency of the wave will ______
Amplitude affects only loudness or intensity of a wave.
19 (P.7B, P.3F) The sound wave produced by a trumpet has a frequency of 440 hertz. What is the distance between successive compressions in this sound wave as it travels through air at Standard Temperature and Pressure? (Air temperature at STP is 330 m/s). ______
The distance between successive compressions is another description of wavelength. Wavelength is 330/440 m which is .75 m.
20 (P.7B, P.2J) What is the speed of the wave in the diagram below if its frequency is 8.0 hertz? ______
Wavelength is the distance between two consecutive crests or troughs. But it is also the distance between two identical points of two consecutive waves. In this question, you had better use the latter definition. According to the definition, there are three waves in the 6 m length. Then the length of a wave is 2 m. That is the wavelength of the wave.
Then speed is what?
21 (P.7B, P.3F) The diagram below represents a periodic wave traveling through a uniform medium. If the frequency of the wave is 2.0 hertz, what is the speed of the wave? ______
This question is a little bit tricky because the 6.0 m long distance does not indicate any exact number of waves. The length includes the distance from a crest to a following crest and the distance from the crest to a trough. It covers one full wave and half wave which is one and a half waves. The length of 1 ½ waves is 6.0 m. The length of a wave is 6.0/1.5 which is 4. So speed is 4 x 2 m/s.
22 (P.7B, P.3F) At an outdoor physics demonstration, a delay of 0.50 second was observed between the time sound waves left a loudspeaker and the time these sound waves reached a student through the air. If the air is at Standard Temperature and Pressure, how far was the student from the speaker? (Air temperature at STP is 330 m/s). ______
Do not use the formula of speed which is the product of wavelength and frequency. Instead, use the formula of speed which is the quotient of distance and time. V=d/t.
Then distance is 330 x 0.5 which is 165 m. Note that the time 0.5 s is the time taken to get to student from the speaker. So do not divide that time by 2, as you did in amphitheater questions where sound came from you and the reflected sound came back to you.
23 (P.7B, P.2H) While playing, two children create a standing wave in a rope, as shown in the diagram below. A third child participates by jumping the rope. What is the wavelength of this standing wave? ______
Any standing wave shows you two similar waves which are incident wave and reflected wave. When you deal with the wavelength of a standing wave, choose one wave of the two waves. Then you will see it has only one trough or crest which means a half wave. If the length of a half wave is 4.30 m, the length of a whole wave is what?
24 (P.7B) As the energy imparted to a mechanical wave increases, the maximum displacement of the particles in the medium ______
Remember that mechanical waves are waves that require medium to travel in. Any energy input increases amplitude of waves only.
25 (P.7B, P.2J) A student generates a series of transverse waves of varying frequency by shaking one end of a loose spring. All the waves move along the spring at a speed of 6.0 meters per second. Which data table correctly identifies the frequencies and wavelengths for the waves created by the student? Since speed remains constant, the product of any combination of frequency and wavelength must remain the same.
A / B / C / DFrequency
(Hz) / Wavelength
(m)
1.0 / 1/6
2.0 / 1/12
3.0 / 1/18
4.0 / 1/24
/ Frequency
(Hz) / Wavelength
(m)
1.0 / 6.0
2.0 / 3.0
3.0 / 2.0
4.0 / 1.5
/ Frequency
(Hz) / Wavelength
(m)
1.0 / 6.0
2.0 / 12.0
3.0 / 18.0
4.0 / 24.0
/ Frequency
(Hz) / Wavelength
(m)
1.0 / 1/6
2.0 / 1/3
3.0 / 1/2
4.0 / 2/3
26 (P.7B, P.2J)The graph below represents the relationship between wavelength and frequency of waves created by two students shaking the ends of a loose spring. Calculate the speed of the waves generated in the spring. ______
/ Choose any point on the line and read its x and y values. The product of x and y values is its speed. The x value of the top dot is 1 and its y value is 5. Then speed is 1 x 5 which is 5.27 (P.7B, P.2J) The diagram below represents a segment of a periodic wave traveling to the right in a steel spring. What is the amplitude of the wave? ______
/Remember the definition of amplitude.
28 (P.7B, P.2J) The diagram below represents a segment of a periodic wave traveling to the right in a steel spring. If a wave crest passes line XY every 0.40 second, the frequency of the wave is ______
/Make sure that you work with the definition of frequency. Frequency is how often or how many per second.
If one wave is per 0.4 second, how many waves per 1 second? It is 1/0.4 which is 2.5 waves per second. Answer is 2.5 Hz.
29 (P.7B, P.2J) The diagram below represents a segment of a periodic wave traveling to the right in a steel spring. What is the wavelength of the wave? ______
/ I told you that this kind of question is a little bit tricky because the given distance does not indicate any exact number of waves. In this case, the length includes the distance from a crest to a following crest and the distance from the crest to a middle line. It covers one full wave and only one fourth wave which is 1 1/4 waves. The length of 1 ¼ waves is 2.5 m. The length of a wave is 2.5/1.25 which is 2. So its wavelength is 2 m.30 (P.7B, P.2H) A stationary research ship uses sonar to send a 1.18 x 103 Hz sound wave down through the ocean water. The reflected sound wave from the flat ocean bottom 324 meters below the ship is detected 0.425 second after it was sent from the ship. What is the speed of sound in the ocean water? ______
Do not confuse v=d/t with v=wavelength x frequency. When distance is given or how far is asked in questions, you have to consider the formula v=d/t. In addition, the time 0.425 is the time required to have the reflected sound. So the time must be divided by 2 to find out the time required for one way only. V = 324 / .2125 which is 1524 m/s.
31 (P.7B, P.2L) The diagram below shows a parked police car with a siren on top. The siren is producing a sound with a frequency of 680 Hz, which travels first through point A and then through point B, as shown. If the sound waves are in phase at points A and B, the distance between the points could be ______
The speed of the sound is 340 m/s. / In phase means “in step.” So a crest of a wave exactly overlaps a crest of another wave and a trough of a wave exactly overlaps a trough of another wave. So The distance between A and B is a multiple of its wavelength.Find the answer which is an exact multiple of the wavelength. By the way, its wavelength is speed/frequency which is .5 m. The answer could be .5, 1.0, 1.5, 2.0 etc.
32 (P.7D, P.3F) The diagram below shows a parked police car with a siren on top. The siren is producing a sound with a frequency of 680 Hz, which travels first through point A and then through point B, as shown. What is the wavelength of the sound produced by the car's siren? ______
The speed of the sound is 340 m/s. /its wavelength is speed/frequency which is .5
33 (P.7B, P.3F) In the diagram below, a water wave having a speed of 0.25 m/s causes a cork to move up and down 4.0 times in 8.0 seconds. If the frequency of the wave doubles, the wavelength of the wave ______
One up and down represents one wave. Four waves in 8.0 seconds indicate a half wave in one second which is its frequency. The wavelength is 0.25/.5 which is .5 m.
35 (P.7D) The diagram below represents a pulse traveling from left to right in a stretched heavy rope. The heavy rope is attached to light rope which is attached to a wall. When the pulse reaches the light rope, its speed will ______
/ I think the speed will increase because the molecule of light rope is lighter than that of heavy rope and kinetic energy is conserved in both types of ropes. KE = ½ mv2.36 (P.7D) As the phase difference between two interfering waves changes from 0˚ to 180˚, the amplitude of the resultant wave 180 degree difference is exactly out of phase. So a crest of a wave meets a trough of another wave and a trough of a wave meets another trough of another wave. The amplitude of the resultant wave is zero.
37 (P.7D, P.3F) The diagram below shows a police car accelerating toward points A and B. The siren is producing a sound with a frequency of 680 Hz, which travels first through point A and then through point B, as shown. As the car accelerates toward point A, the frequency of the sound heard by an observer at point A would
The speed of the sound is 340 m/s. / ______38 (P.7D, P.2J) The wave shown below is moving in the direction indicated. What might be happening to cause the wave to look like this?
/ A / The wave is traveling into a new medium, causing the frequency to increase.B / The source of the vibration is slowing down as the wave travels through a uniform medium.
C / The wave loses energy as it travels through a uniform medium
D / The wave is traveling into a new medium, causing the frequency to decrease.
39 (P.7D, P.2J) Two waves, A and B, travel in the same direction in the same medium at the same time. The resultant wave