Excursions in Physics
Third Hour Exam
March 31, 20023

Statistics:
High: 96
Mean: 76
Low: 46

For every question, also consider as a possible answer
E) none of the above

Be sure to fill in everything on the “scantron” sheet — fill in the circles for your name and your social security number. All I want is the “scantron” sheet; you may keep the exam questions.

For every question, also consider as a possible answer
E) none of the above

1. Increasing the mass of a simple pendulum harmonic oscillator makes its period
A) longer
B) shorter
C) unchanged

2. Increasing the mass m of a mass-and-spring simple harmonic oscillator makes its period
A) longer
B) shorter
C) unchanged

3. A mass-and-spring simple harmonic oscillator has maximum kinetic energy
A) at its equilibrium position
B) when its displacement equals its amplitude
C) half way between equilibrium and amplitude
D) three-fourths of the way between equilibrium and amplitude

4. The period of a simple harmonic oscillator is
A) the time required for one oscillation
B) the number of oscillations per second
C) the energy stored in the oscillations
D) the maximum distance moved from equilibrium

5. The frequency of a certain oscillator is 100 Hz; its period is
A) 0.1 s
B) 0.01 s
C) 0.001 s
D) 0.0001 s

6. There are "signals" of many different frequencies coming into the antenna of your radio. Only the one with a particular frequency is amplified and produces the sound you listen to. This is an example of
A) resonance
B) damping
C) timbre or quality
D) fundamental regeneration

7. Which of the following is a longitudinal wave?
A) light
B) wave on a string
C) sound
D) all of the above

8. A wave has a frequency of 50 Hz and a wavelength of 0.5 m. It has a wave speed of
A) 2.5 m/s
B) 10 m/s
C) 25 m/s
D) 100 m/s

9. A wave has a frequency of 32 Hz and travels 4 m in one second. It has
A) a wave speed of 128 m/s and a wavelength of 8 m.
B) a wave speed of 128 m/s and a wavelength of 1/8 m.
C) a wave speed of 4 m/s and a wavelength of 1/8 m
D) a wave speed of 4 m/s and a wavelength of 8 m

10. A wave has a frequency of 25 Hz and travels 5 m in one second. It has
A) a wave speed of 100 m/s and a wavelength of 5 m.
B) a wave speed of 100 m/s and a wavelength of 1/5 m.
C) a wave speed of 5 m/s and a wavelength of 1/5 m
D) a wave speed of 5 m/s and a wavelength of 5 m

11. For standing waves on a string,
A) a node is located at each end
B) a whole number times half the wavelength equals the length of the string
C) the whole "pattern" of standing waves occurs only for certain frequencies
D) all of the above

12. For standing waves on a string, the distance between adjacent nodes is always
A) the length of the string
B) one wavelength
C) one half the wavelength
D) half the length of the string

13. For standing waves on a string, the distance between adjacent antinodes is always
A) half the length of the string
B) one half the wavelength
C) one wavelength
D) the length of the string

14. A bobber on a fishing line oscillates up and down two (2) times per second as waves pass by. The waves have a wavelength of 25 cm. The waves are traveling at
A) 12.5 cm/s
B) 25 cm/s
C) 50 cm/s
D) 100 cm/s

15. Sound is
A) an electromagnetic wave
B) a polarized wave
C) a longitudinal wave
D) all of the above

16. " Infrasonic" means
A) lower than the range of human hearing
B) higher than the range of human hearing
C) faster than the speed of sound
D) slower than the speed of sound

17. Bats and dolphins use echolocation to navigate or the find food or to find their way without relying on sight. The frequencies they use are
A) supersonic
B) infrasonic
C) ultrasonic
D) microsonic

18. The range of human hearing is about
A) 10 Hz to 100 Hz
B) 50 Hz to 500 Hz
C) 50 Hz to 20 kHz

k means kilo as in kilohertz or kilogram

There are 1,000 grams in a kilogram.

There are 1,000 Hz in a kHz.

D) 1 kHz to 100 kHz

19. Ella Fitzgerald made commercials for Memorex in which she used her voice to break a wine glass. This is an example of
A) echolocation
B) supersonic sound
C) ultrasonic frequencies
D) resonance

20. Beats are heard when two sounds have
A) nearly the same amplitude
B) nearly the same frequencies
C) twice the amplitude
D) exactly twice the frequency

21. The fundamental frequency present in a sound is the
A) sum of all the frequencies mixed together
B) difference between the highest and lowest frequencies present
C) lowest frequency present
D) highest frequency present

22. The fundamental frequency present in a sound determines the
A) quality or timbre
B) amplitude or loudness
C) pitch or note
D) all of the above

23. The "pitch" of a sound is determined by its
A) overtones frequencies
B) harmonics frequencies
C) fundamental frequency
D) resonance frequency

24. The quality or timbre -- the distincitive characteristic -- of a sound is determined by its
A) overtones or harmonics
B) amplitude or loudness
C) attack or decay
D) fundamental frequency

25. Consider a musical note of 262 hertz (middle “C”). Two octaves higher is represented by a musical note of
A) 131 Hz; this is one ocatave lower.
B) 524 Hz; this is one ocatave higher.
C) 1048 Hz
D) 1572 Hz

26. Suppose you play a note of a certain pitch on a violin. You can produce a higher-pitched note by
A) shortening the length of the string that is allowed to vibrate
B) decreasing the tension of the string (loosening the string)
C) increasing the linear mass density of the string (using a "heavier" string)
D) lengthening the part of the string that vibrates.

27. When a flute sound is viewed on an oscilloscope, the sound wave is very smooth. This is because
A) the amplitude is always small (flutes are quiet)
B) it has practically no overtones or harmonics
C) its fundamental frequency has a smaller amplitude than its second and third harmonics
D) its harmonics get larger and larger

28. When a trumpet sound is viewed on an oscilloscope, the sound wave is very complex. This is because
A) the amplitude is always large (trumpets are loud)
B) it has practically no overtones or harmonics
C) it has many overtones or harmonics
D) its has only even-numbered overtones or harmonics

29. A petroleum geologist might use a very carefully calibrated simple pendulum to do “prospecting” for a large pool of oil. If this “prospector” were over such a large pool of oil, she or he would find the period of this simple pendulum to be
A) longer

Directly above the large oil pool, the acceleration due to gravity, g, will be slightly less than normal.

this means the period T will be larger or longer than normal.
B) shorter
C) unchanged
than normal.

30. Increasing the length of a simple pendulum makes its period
A) longer

B) shorter
C) unchanged

31. The period of a simple pendulum depends upon its
A) mass
B) amplitude
C) length

32. Ordinary household electricity is alternating current with a frequency of 60 Hz. Its period is
A) 60 cycles per second.
B) 120 cycles per second.
C) 0.0333 s.
D) 0.0167 s.

33. If you apply a force to an oscillator at its natural frequency, you will produce motion
A) at exactly twice that frequency
B) at exactly one-half that frequency
C) with an amplitude that dies out or gets smaller.
D) with large amplitude

This is resonance.

34. As the amplitude of a simple harmonic oscillator increases, its frequency
A) increases
B) stays the same
C) decreases

35. Which of these waves can not be polarized?
A) light
B) sound

Sound is a longitudinal wave.
C) electromagnetic
D) wave on a string

36. Individual disturbance that make up a longitudinal wave
A) move perpendicular to the direction of the wave
B) move parallel to the direction of the wave
C) move in circles
D) move in ellipses

37. On a string that is 1.0 m long, standing waves may be formed with the following wavelengths:
A) 1.0 m, 2.0 m, 3.0 m
B) 1.0 m, 2.0 m, 4.0 m
C) 1.0 m, 0.67 m, 0.40 m

D) 1.0 m, 0.8 m, 0.75 m

38. Two waves can pass through each other; this is described by or as
A) an elastic collision
B) an inelastic collision
C) a supersonic collision
D) superposition

39. Suppose you strike two tuning forks and hear a beat frequency of 2 Hz. You know that one of the tuning forks is tuned to 440 Hz. The other tuning fork must have a frequency of
A) 2 x 440 Hz = 880 Hz.
B) 440 Hz / 2 = 220 Hz
C) (440 + 2) Hz = 442 Hz

Of course, (440 - 2)Hz = 438 Hz would also produce the same beat frequency.
D) (440)2 = 193,600 Hz

40. If you double the frequency of a sound, you also double its
A) amplitude
B) wavelength; the wavelength is reduced to one-half
C) speed
D) all of the above

E) None of the above.

41. If you double the frequency of a sound, you reduce to one-half its
A) amplitude
B) wavelength
C) speed
D) all of the above

42. Sound travels fastest in
A) vacuum
B) air (gas)
C) water (liquid)
D) steek (solid)

43. “Supersonic” means
A) above the range of human hearing.
B) below the range of human hearing.
C) slower than the speed of sound.
D) faster than the speed of sound.

44. When or where two sound waves add together to produce a region of high volume or large amplitude, we describe this as
A) destructive interference.
B) constructive interference.
C) reconstructive interference.
D) demonstrative interference.

45. Think of the sound produced when you blow across the top of a Coke bottle. As you add water to the Coke bottle, so the column of air in the bottle becomes shorter, you expect the pitch of the sound produced to
A) increase.
B) remain the same.
C) decrease.

46. Individual disturbance that make up a transverse wave
A) move perpendicular to the direction of the wave
B) move parallel to the direction of the wave
C) move in circles
D) move in ellipses

47. Simple harmonic motion is a common response for a disturbance from
A) unstable equilibrium.
B) constructive equilibrium.
C) stable equilibrium.
D) destructive equilibrium.

48. Damped harmonic motion means
A) harmonic motion connected with a fluid.
B) harmonic motion under water!
C) harmonic motion with a decreasing amplitude.
D) harmonic motion with an increasing frequency.

49. Amplitude is
A) frequency x period.
B) frequency / period.
C) maximum displacement from equilibrium.
D) maximum frequency.

50. Compared to ordinary sound, ultrasound has a
A) greater speed.
B) greater wavelength.
C) smaller wavelength.
D) slower speed.