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Do the following problems on the CAPA computer graded homework ...

By Manuel Gibson,2014-07-08 23:55
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Do the following problems on the CAPA computer graded homework ...

SCI 202: Physics of Modern Technology: Module 6

Periodic Motion Problems

NAME:

Solve the following problems. Show all your work and describe what you are trying to do. Partial credit may be awarded. This assignment is worth a total of 80 points.

1. For a massive block oscillating up and down on a spring like in Fig 9.1.5, label how the following

changes would affect the oscillation period. Label it as making it shorter (S), longer (L), or unchanged

a. Reducing the mass.

b. Taking it to the moon where gravity is weaker.

c. Weakening the spring (reducing the spring constant).

d. Making the amplitude of the oscillation larger.

2. For a pendulum as in Fig 9.1.2: label how the following changes would affect the oscillation period.

Label each as making the period shorter (S), longer (L), or unchanged (U). Explain your response.

a. Taking it to a planet where gravity is larger.

b. Increase the mass hanging on the pendulum.

c. Making the pendulum shorter.

d. Reducing the amplitude of the oscillation (assuming that it was not very big to start with).

3. The frequency of the tone produced by a violin string is higher (H), lower (L) or unchanged (U) if we

make the following changes (note that here we are asking about the frequency, whereas on the

earlier problems we were asking about the period of the oscillation, which is just the inverse of the

frequency) :

a. Making the string shorter.

b. Making the string thicker.

c. Pressing the string down on the fingerboard.

d. Reducing the tension of the string.

4. I take a violin and make an exact copy of it, except that it is bigger. The strings are identical except for

the length; they have the same material and the same tension. If the new violin is 2.30 times the size

of the original, at what frequency would the string that was previously the A4 string (that is 440 Hz on

a regular violin) oscillate? Use units of "Hz." Explain your response.

5. If your hearing cuts off at 17440 Hz, what is the highest harmonic of E5 string you can hear? The

answer is an integer without units. Hint: The E5 string vibrates at 660 Hz. Explain your response.

6. The frequency of the sound coming from the organ pipe is higher (H), lower (L) or the same (S) if we

make the following changes to the organ:

1 2007 Jones International University;, Ltd.

SCI 202: Physics of Modern Technology: Module 6

a. Moving the organ to a higher elevation.

b. Making pipe longer.

c. Blowing more air across the pipe.

d. Exciting a harmonic of the pipe rather than fundamental mode.

7. Label the following statements as true (T) or false (F). Explain your responses.

a. Wrapping steel piano strings with fine copper wire will reduce the pitch.

b. A violin string can only produce a single frequency unless the tuning is changed. c. As a violin string vibrates, its motional energy is changing rapidly with time. d. High pitched violin strings are the most likely to break.

e. Most of the sound from a violin comes directly from the strings.

8. The global positioning system (GPS) uses clocks to tell you wherever you are on earth to within

several feet. The GPS is a bunch of very accurate atomic clocks that are in satellites whose positions

are well known. They send out radio pulses at very precise times, and a GPS receiver detects the

time it takes for the pulses from all the different satellites to reach it. This tells it how far it is from each

of the satellites. Then it does a bunch of fancy geometry to figure out its position. Let’s consider just

one satellite so you do not have to do any geometry. You are somewhere in the middle of the country

and a satellite that is a short distance above San Francisco sends out a pulse that your GPS receiver

tells you took 0.002 seconds to reach you. Since you know that the radio signal travels at the speed

of light, how far does this mean you are from San Francisco (neglect the distance between San

Francisco and the satellite)? Explain your response.

9. Which of the following objects could be used to construct a functional clock?

a. A superball bouncing up and down many times on a hard floor.

b. A very low frequency tuning fork.

c. A ribbon fluttering back and forth in the wind.

d. A car that is bouncing up and down as it drives over a bumpy road.

e. A chair hanging by a bungee cord out a window.

10. If a violin string is stretched out with a certain tension and then glued between two concrete pillars,

what change would there be in the sound it produced when bowed compared to when it was attached

with the same tension to a violin?

a. It would produce a higher frequency.

b. It would produce fewer harmonics.

c. It would give a much quieter sound.

d. The string would move much less.

e. It would produce a much louder sound.