Mechanical Waves and Sound Review Questions PDF

Mechanical Waves and Sound Review \_\_\_\_1. The speed of a wave depends on \_\_\_\_\_\_ a\. its frequency. b\. its wavelength. c\. the medium. d\. its amplitude e\. a, b, and c \_\_\_\_2. The time needed for a wave to make one complete cycle is called the wave\'s \_\_\_\_\_ a\. frequency....

Mechanical Waves and Sound Review \_\_\_\_1. The speed of a wave depends on \_\_\_\_\_\_ a\. its frequency. b\. its wavelength. c\. the medium. d\. its amplitude e\. a, b, and c \_\_\_\_2. The time needed for a wave to make one complete cycle is called the wave\'s \_\_\_\_\_ a\. frequency. b\. period. c\. wavelength. d\. velocity. e\. amplitude. \_\_\_\_3. A skipper on a boat notices wave crests passing the anchor chain every 5 seconds. The skipper estimates the distance between crests is 15 m. What is the speed of the water waves? a\. 2 m/s b\. 3 m/s c\. 5 m/s d\. 15 m/s e\. 75 m/s \_\_\_\_4. A standing wave is created in a string because a\. the speed of propagation of waves is so slow that it appears "standing". c\. As the string is attached the oscillation has nowhere to go, so it stops. \_\_\_\_5. Above is a taut rope that had the left end shaken to produce a small pulse that travels to the end of the rope in time *t*. The pulse is allowed to die down and the person then shakes the rope again. Which of the following would create a pulse that gets to the wall in less time than the original pulse?\ a. Move the hand up and down more quickly but move it the same amount.\ b. Move the hand up and down a larger distance but in the same amount of time.\ c. Put more force, but not increasing tension, into the pulse.\ d. All of these will decrease the time for the pulse to get to the end.\ e. None of these will decrease the time for the pulse to get to the end. \_\_\_\_6. You are shaking the end of a spring up and down and are able to get 2 antinodes on the spring when your frequency is 6 Hz. At what frequency will you be able to get 3 antinodes?\ a. 8 Hz b. 9 Hz c. 12 Hz d. 18 Hz d. 24 Hz [\_\_ \_] 7. If the frequency of the waves on a string are doubled the [wavelength] will be \_\_\_\_\_\_\_ [­­­\_\_\_\_]8. If the tension in a stretched string is increased by a factor of 4, the wave speed will be \_\_\_ [\_\_\_\_]9. If a guitarist switches to a string of the same length but with one-fourth the linear density the wave speed will be \_\_\_\_\_\_ [ ] 10. If the frequency of a wave on a string is doubled, the wave speed will be \_\_\_\_\_\_ [\_\_\_\_]11. If the amplitude of a wave on a string is doubled, the wave speed \_\_\_\_\_\_ [\_\_\_\_]12. If the length of a wave on a string is doubled, the wave speed will be \_\_\_\_\_\_\_\_ **For questions 13-15**, refer to diagram below in which a standing wave is established on a 1.6 m long string: \_\_\_\_13. The number of nodes is: a\. 2 b. 3 c. 4 d. 5 e. 6 \_\_\_\_14. The wavelength is: a\. 0.4 m b. 0.8 m c. 1.2 m d. 1.6 m e. 3.2 m \_\_\_\_15. If the frequency of vibration is 80 Hz, the speed of the wave in the wire is: a\. 10 m/s b. 64 m/s c. 128 m/s d. 320 m/s e. 640 m/s 16\. The diagrams below show pulses as they head toward each other. Using the principle of superposition, show the appearance of the string at the instant the centers of the pulses overlap. Two ropes XP and PY are joined together with a knot at P. An upward pulse such as that shown in the first figure, left, is passed along the string to the knot, where part is transmitted and part is reflected. Shortly thereafter, the two pulses leaving the knot are moving as shown in the figure to the right. (sizes may not be correct) [ ] 17. The conclusion that can be drawn from the figures is that: a\. the pulse arrived from X, XP is denser than PY b\. the pulse arrived from X, XP is less dense than PY c\. the pulse arrived from Y, XP is denser than PY d\. the pulse arrived from Y, and XP is less dense than PY \_\_\_\_18. The end of a spring attached to a wall is shaken to produce a pulse like the one below. When the pulse returns it will appear most like a\. b. c. d. e. \_\_\_\_19. To the right is a pulse on a high density string heading toward a low density string. Soon after the pulse arrives at the low density [ ] string the two strings will appear most like: a\. b. c\. d. e. \_\_\_\_20. Pulses A and B below are traveling at.50 m/s on a rope as shown in the diagram. In 2 seconds, the rope will appear most like: a. b\. c. 22\. Maggie Zine plucks her thickest guitar string and it vibrates at the fundamental frequency. a. Before placing the string on her guitar Maggie measured the string and found it to be 85.0 cm long and it had a mass of 4.67 g. When she placed the string on the guitar she found the length that vibrated to be 53.0 cm. Maggie carefully adjusted the tension in the string until the string vibrated at 82.4 Hz. b. How much tension was in the guitar string? 23\. Two bugs are sitting on the guitar string 50cm long. Ralph is 5 cm from an end and Corrina is 5 cm from Ralph (but not at the end). When the string vibrates, Ralph has to hang on for dear life while Corrina doesn\'t move. c. How many nodes are on the string? [ ] d. 24. Text Description automatically generated Your class has the experimental setup shown above. The oscillator has variable frequencies and tells you the frequency it is emitting at any given time. The hanging weight, length of string, and frequency can be changed if you want. Your goal is to determine the speed of the wave on the string by making a graph whose slope is equal to the speed of the wave on a string. Answer the questions below to develop a procedure for determining the speed of the wave on a string. a. Sketch what your final graph (make sure to label the axes) should look like. Please note a sketch indicates what is on each axis and the general shape of the graph. It is NOT a scaled graph with accurate data points. b. On the picture above, label with the appropriate variables, what data you will need to collect/measure and how to do so. c. Neatly, in a bulleted list, describe the full set of procedures, making sure to include what data to collect/measure, what calculations to make, and how to construct the graph. Use the information below to answer questions 25 -- 28: The fundamental frequency of middle C is 256 Hz. The speed of sound in air at room temperature is about 340 m/s. 25. If the speed of the waves through a string is 115 m/s, then what length of string would have a fundamental frequency of middle C? a. 11 cm b. 22 cm c. 33 cm d. 44 cm e. 66 cm 26. What length of open pipe would have a fundamental frequency of middle C? a. 11 cm b. 22 cm c. 33 cm d. 44 cm e. 66 cm 27. What length of closed pipe would have a fundamental frequency of middle C? a. 11 cm b. 22 cm c. 33 cm d. 44 cm e. 66 cm 28. What would the next harmonic be for the closed pipe? a. 128 Hz b. 256 Hz c. 384 Hz d. 512 Hz e. 768 Hz Use the information below to answer questions 29-30: An ambulance is coming towards you with its sirens blaring. 29. The pitch you hear is a. Louder than the pitch emitted b. Softer than the pitch emitted c. Higher than the pitch emitted d. Lower than the pitch emitted 30. The pitch you hear is e. Increasing f. Decreasing g. Staying the same h. Impossible to determine [ ] 31. To the right is a speaker that is turned off. The speaker is then turned on and vibrates at a constant low frequency. Which of the following describes the motion of the particle after the speaker was turned on?\ A) The dust particle moves back and forth\ B) The dust particle moves up and down\ C) The particle moves steadily to the right\ D) The dust particle does not move\ E) The dust particle moves in a circle [ ] 32. Pairs of tuning forks are struck at the same time. For which of the following conditions are the two forks the closest in frequency? (A) forks that produce 1 beat/sec (B) forks that produce 2 beats/sec (C) forks that produce 4 beats/sec (D) forks that produce 10 beats/sec [ ] 33. If the fundamental frequency on a tube open on both ends is 250 Hz, the first overtone is (A) 125 Hz (B) 250 Hz (C) 500 Hz (D) 750 Hz [ ] 34. What is obtained if a force is applied to an object at the natural frequency of the object? (A) resonance (B) the doppler effect (C) longitudinal waves (D) transverse waves [ ] 35. Interference of waves going toward a boundary and those that have reflected off the boundary is necessary to produce:\ (A) the doppler effect (B) beats (C) rarefactions (D) standing waves 36\. A pair of tuning forks are struck and a beat frequency of 4 beats/sec is heard. If one of the tuning forks is 440 Hz, what are all of the possibilities for the other?