CP Major Test Chapter 25: Vibrations and Waves

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2.52

Short Answer (140)

Answer the questions below on your own paper. Be sure that each part of each answer is in a complete sentence. Be sure your answers are done clearly in ‘a’, ‘b’, ‘c’ bulleted format. Answer each numbered question on its own page. DO NOT put more than one numbered answer on a page.

1. Consider a transverse wave.

a) Draw a transverse standing wave that is 2.5 l long.

b) Label the following on your drawing: a crest, a trough, a node and an antinode.

c) How many nodes are there on your wave; how many antinodes?

d) Indicate 1 l on your wave.

2. Consider a transverse wave and a longitudinal wave.

a) What kind of wave is a wave on a rope?

b) What kind of wave is a sound wave?

c) In which kind of wave does the wave move in the same direction as the medium?

d) Draw an example of the wave from part ‘c’ that is 1.5 l long.

e) Why is there no sound in space?

3. Consider the Doppler effect:

a) To what two properties of a wave does the Doppler Effect refer?

Suppose you are in your brand new red Mustang driving towards the ringing bells of Green Acres Baptist Church. To an observer standing in the church yard the pitch of the bells is constant.

b) What happens to the speed of sound as you approach the church in your red Mustang?

c) What happens to the pitch of the bells as you approach the church in your red Mustang?

d) What happens to the wavelength of the sound wave as you drive away from the church in your red mustang?

e) What kind of waves demonstrate the Doppler Effect?

PART III True/False (30)

Indicate whether the statement is true or false. Mark your answer document ‘A’ for true and ‘B’ for false.

PART IV Rewrite (60)

On your own paper rewrite the false statements so that they will be true. Be sure to address all of the areas of the false statement that are false. You will receive ten (10, 5+5, X) points for each correctly rewritten statement. Do NOT copy the false statements nor is it necessary to rewrite the true statements.

4. The time it takes for a pendulum to swing back and forth one time is its period.

5. The amplitude of a wave is the total distance from the bottom of a trough to the top of a crest.

6. The distance between two successive points on a wave, for example from crest to crest, is called the frequency of that wave.

7. The period of a wave tells you how many times a sound source vibrates every second.

8. If a wave, such as a sound wave, vibrates in the same direction as the medium through which it is moving that wave is a longitudinal wave.

9. Light waves are an example of longitudinal waves.

10. The SI unit for frequency is the Hertz (Hz), the SI unit for period is the second (s) and the SI unit for wavelength is the meter (m).

11. When one wave constructively interferes with another wave the amplitude of the resulting wave is always increased.

12. A standing wave always has the same number of nodes as it has antinodes.

13. As a train approaches you while blowing it’s whistle the pitch of the whistle gets lower and lower.

PART V: Multiple Choice (60)

Identify the choice that best completes the statement or answers the question.Carefully place your answer choice on your answer document.

14. The time needed for a wave to make one complete cycle is its

a.	frequency	c.	wavelength
b.	period	d.	amplitude

15. Note the figure below. Which choice best finishes the statement?

a.	frequency	c.	wavelength
b.	period	d.	amplitude

16. A Hertz is an SI unit of ______?

a.	period	c.	wavelength
b.	frequency	d.	amplitude

17. Note the figure below. What kind of wave is being generated in the rope?

a.	A longitudinal wave	c.	A standing wave
b.	A transverse wave	d.	A surface wave

18. Sound is an example of a _______?

a.	longitudinal wave	c.	standing wave
b.	transverse wave	d.	Doppler wave

19. Note the figure below. Which choice best describes what this series of pictures is showing? (‘S’ stands for source.)

a.	A standing wave	c.	The Doppler effect
b.	Wave interference	d.	Resonance

20. Note the figure below. This picture represents a standing wave on a rope. Where can you touch this rope without disturbing the wave?

a.	At the nodes	c.	At either the nodes or the antinodes
b.	At the antinodes	d.	At any place along the rope

21. Note the figure below. Which train station will hear the pitch of the train whistle as lower than it actually is?

a.	Train station A	c.	Both stations will hear the same pitch
b.	Train station B	d.	Neither station will hear the train whistle

22. If you double the frequency of a vibrating object, its period ________.

a.	doubles	c.	is quartered
b.	halves	d.	is squared

23. As the sound of a car’s horn comes toward you, the pitch of the horn seems to

a.	get higher	c.	stay the same
b.	get lower	d.	get louder

24. The Doppler effect is the change in observed frequency due to _______?

a.	the type of medium the wave is in	c.	the type of wave
b.	the original frequency of the source	d.	the motion of the source or observer

25. When a sound source moves toward you, what happens to the wave speed?

a.	it increases	c.	it stays the same
b.	is decreases	d.	it gets louder

26. The light from the left side of the sun is shifted in the red while light from the right side of the sun is shifted in the blue. This is compelling evidence that our sun is____.

a.	stationary	c.	moving from left to right
b.	rotating	d.	moving from right to left

27. Note the grandfather clock below. The pendulum inside the clock determines whether the clock runs fast or slow. As you can see this clock is running fast! What should be done with the mass on the pendulum?

a.	the mass should be raised, making the pendulum shorter	c.	replace the mass with a lighter pendulum
b.	the mass should be lowered, making the pendulum longer	d.	replace the mass with a heavier pendulum

28. In order for a wave to be produced something must _____.

a.	move	c.	roll
b.	vibrate	d.	accelerate

29. You dip your finger repeatedly into water and make waves. If you dip your finger more frequently, the wavelength of the waves _______.

a.	shortens	c.	stays the same
b.	lengthens	d.	creates a super wave

30. During a single period, the distance traveled by a wave is _______.

a.	one-half wavelength	c.	two wavelengths
b.	one wavelength	d.	1.75 wavelengths

31. The velocity of a wave is determined by _____.

a.	the frequency	c.	the medium through which the wave is traveling
b.	the wavelength	d.	the product of the frequency and the wavelength

32. Note the two pendulum below. Which pendulum has the shorter period?

a.	Pendulum A	c.	Both pendulum will have the same period
b.	Pendulum B	d.	the one with the least mass

33. What is the velocity of a wave that has a frequency of 400 Hz and wavelength of 0.84 m?

a.	336 m/s	c.	400.84 m/s
b.	399.16 m/s	d.	476 m/s

CP Major Test Chapter 25: Vibrations and Waves

Answer Section

SHORT ANSWER

1. a) This is a standing wave that is 2.5 l long

b) This is a 2.5 l long wave with a crest, a trough, a node and an anti node indicated:

c) On a 2.5 l standing wave there are 6 nodes and 5 antinodes.

d) This is a 2.5 l standing wave with one l marked on it:

2. Considering a transverse wave and a longitudinal wave:

a) A wave in a rope is a transverse wave.

b) A sound wave is a longitudinal wave.

c) A longitudinal wave moves in the same direction as the medium.

d) This is a drawing of a 1.5 l longitudinal wave:

e) There is no sound in space because there is no medium for sound to travel through. Space is essentially a vacuum.

3. Considering the Doppler Effect:

a) The wavelength and frequency of a wave are affected by the Doppler Effect.

b) The speed of sound is not affected as I approach the church in my RM.

c) The pitch of the bells is higher as I approach the church in my RM.

d) The wavelengths of the sound waves get longer as I drive away from the church in my RM.

e) All waves demonstrate the Doppler Effect.

TRUE/FALSE

4. T

5. F

The amplitude of a wave is the distance from the he midpoint of the wave to either the top of a crest or the bottom of a trough.

6. F

The distance between two successive points on a wave, for example from crest to crest, is called the wavelength of that wave.

7. F

The period of a wave tells you how long it takes a sound source to vibrate one wavelength.

8. T

9. F

Sound waves are an example of longitudinal waves OR Light waves are an example of a transverse wave.

10. T

11. T

12. F

A standing wave always has one more node than it has antinodes.

13. F

As a train approaches you while blowing it whistle the pitch of the whistle gets higher and higher.

MULTIPLE CHOICE

14. B

15. C

16. B

17. B

18. A

19. B

20. A

21. B

22. B

23. A

24. D

25. C

26. B

27. B

28. B

29. A

30. B

31. C

32. A

33. A