# Hall/Archibald CLASS SET PLEASE DO NOT WRITE on THIS

Hall/Archibald CLASS SET—PLEASE DO NOT WRITE ON THIS

2/16-17/11

## waves and sound quiz

### Multiple Choice

1)  A stretched spring attached to two fixed points is compressed on one end and released, as shown at right. The resulting wave travels back and forth between the two fixed ends of the spring until it comes to a stop. This mechanical wave is an example of a:

a)  Transverse wave.

b)  Longitudinal wave.

c)  Superpositioned wave.

d)  Refracted wave.

2)  A tuning fork is used to produce sound waves with a frequency of 440 hertz. The waves travel through the air at 344 m/s. What will happen when a different tuning fork is used to produce sound waves of 512 hertz?

a)  The velocity of the sound will increase

b)  The velocity of the sound will decrease

c)  The wavelength of the sound will increase

d)  The wavelength of the sound will decrease

3)  Which of the following affect the velocity of a wave? (circle all that apply):

a)  Frequency

b)  Period

c)  Wavelength

d)  Amplitude

e)  Medium

4)  The graph at right depicts the relationship between wave energy and wave amplitude. How is the energy of the wave affected if the amplitude of the wave increases from 2 meters to 4 meters?

a)  It is halved.

b)  It is doubled.

d)  It remains the same.

5)  One end of a horizontal string is caused to oscillate vertically while the other end is attached to a fixed object. The wave that travels along the string is an example of:

a)  An electromagnetic wave.

b)  A transverse wave.

c)  A microwave.

d)  A longitudinal wave.

6)  Astronauts on the Moon would not be able to hear a landslide because:

a)  The lunar dust deadens sounds.

b)  Intensive sunlight destroys sound waves.

c)  The magnetic field of the Moon is too weak to carry sound.

d)  Air molecules on the Moon are too far apart to carry sound.

7)  A wave is transmitted from a less dense medium to a denser medium. The wave will most likely:

a)  Speed up

b)  Slow down

c)  Increase frequency

d)  Decrease wavelength

8)  A man is standing by the side of the road when a Porsche 911 drives by, blowing its horn. The Porsche is driving away from the man on the ground. Compared to the frequency of the sound that the driver of the Porsche hears, the man standing on the ground hears a sound with:

a)  The same wavelength.

b)  More variation in tone.

c)  Greater amplitude.

d)  A lower frequency.

### Short Answer and Problem Solving

Do THREE (3) of the questions below—1 problem solving, 1 short answer, and a third of your choice.

Use complete sentences and RAP format (rephrase, answer, provide support/examples).

9)  Two ambulances are driving down the road with their sirens on. The sirens on each ambulance are producing an identical frequency. The first ambulance is going 75 mph, and the second ambulance is going 50 mph. Draw a picture of the sound waves generated by each, and state which one will sound like it is producing a higher frequency and WHY.

10)  Explain the phenomenon of beats: what they sound like, and why they occur. Draw a graph of two different frequencies to support your answer.

11)  Describe constructive and destructive interference in waves. Provide an example to support your description.

#### Problem Solving

For each of the problems below, you MUST DiTEST your answer! Answers without diagrams will only receive half credit. Label all variables in the diagram!

12)  A transverse wave is observed to be moving along a lengthy rope. Adjacent crests are positioned 3.7 m apart. Exactly 7 crests are observed to move past a given point along the medium in 9.7 seconds. Determine the velocity of these waves.

13)  In a physics lab, a rope is observed to make 135 complete vibrational cycles in 20 seconds. The length of the rope is 2.5 meters and the measurements are made for the 5th harmonic (with five equal length sections).

a)  Solve for the frequency of the waves

b)  Solve for the wavelength