Unit 11 Quiz#1
This quiz is rather lengthy. If you get stuck on a section, proceed to he next section. Use complete sentences where appropriate and when a calculation is involved, please show your work.
Part I: Matching
Indicate which wave characteristic the following statements refer to by placing a letter in each blank.
______ (1) May be expressed in units of Hz.
______ (2) Number of waves passing by a given point per unit time.
______ (3) Equals f x w
______ (4) Reciprocal of the frequency.
______ (5) Indicator of the amount of energy in a wave.
______ (6) Depends only upon the medium through which a wave is traveling.
______ (7) Horizontal distance between adjacent troughs.
______ (8) Maximum displacement from the rest position.
Part II: Fill in the Blank
Read the following paragraph and select the appropriate word to fill in the blank.
When a wave reaches a boundary between two medium, part of the wave is reflected and part of the wave is transmitted. The amount of reflection which occurs ________________ (increases, decreases) as the similarity of the two medium increases. The more similar the two medium, the ___________________ (greater, smaller) that the amplitude of the reflected wave will be. The reflected wave may be inverted or erect depending upon the relative _____________________ (rigidity, compressibility, propensity) of the two medium. When a wave travels along a slinky towards a wall, the reflected wave will be _________________ (inverted, erect). When a wave travels from a slinky to a string, the reflected wave will be _______________ (inverted, erect). When a wave is transmitted through a boundary, its speed _________________ (changes, remains the same) and its frequency _________________ (changes, remains the same). As the wave enters the new medium, the amplitude will _____________ (always, never, occasionally) increase.
Part III: Multiple Choice
1. An ocean wave has an amplitude of 2.5 m. Weather conditions suddenly change such that the wave has an amplitude of 5.0 m. The amount of energy transported by the wave is __________.
2. A sound wave, traveling through water, has a frequency of 220 Hz. If another sound wave is generated with a frequency of 440 Hz, the new sound wave will have a wavelength which is ______________ the distance of the former wave.
3. Two waves are traveling through a container of nitrogen gas. Wave A has a wavelength of 1.5 m. Wave B has a wavelength of 4.5 m. The velocity of wave B must be __________ the velocity of wave A.
4. Two waves are traveling through a container of nitrogen gas. Wave A has a wavelength of 1.5 m. Wave B has a wavelength of 4.5 m. The frequency of wave B must be __________ the frequency of wave A.
5. Two waves are traveling through a container of nitrogen gas. Wave A has an amplitude of .1 cm. Wave B has an amplitude of .2 cm. The energy transported by wave B must be __________ the energy transported by wave A.
6. A fly flaps its wings back and forth 150 times every second. The period of a wing flap is ________ sec.
7. A tennis coach paces back and forth along the sideline 10 times in 2 minutes. The frequency of his pacing is ________ Hz.
8. A tennis coach paces back and forth along the sideline 10 times in 2 minutes. The period of his pacing is ________ seconds.
Part IV: Short Answer and Problem-Solving
1. When two waves meet along the same medium, ________________ (interference, refraction, dispersion) occurs.
2. Use the principle of superposition to determine the wave which results from the combination of the two waves in the following diagram.
3. Consider two waves traveling through air. One has a frequency of 750 waves/sec while the other has a frequency of 250 waves/sec. Which wave travels fastest? Explain using complete sentences.
4. If the speed of sound is 340 m/sec and the wavelength of a sound is 5.0 m, what is the frequency of the sound?
If this same sound entered into water, what would be the frequency? Explain your reasoning.
5. Radio waves travel at the speed of light, 3.0 x 108 m/sec. What is the wavelength of a radio wave from an AM station broadcasting at a frequency of 750 kHz? (NOTE: 1 kHZ = 1000 Hz) (2 pts.)
6. A certain ocean wave has a frequency of 0.05 Hz and a wavelength of 10 meters. What is the wave's speed?
7. A wave travels from one medium to another, and the wavelength decreases. What happens to the velocity and the frequency?
8. Consider the wave shown below. Using a ruler, sketch the following
9. Sketch a slinky with two pulses traveling through it in such a manner that constructive interference will occur. Indicate the direction which each pulse is moving.
10. Sketch a slinky with two pulses traveling through it in such a manner that destructive interference will occur. Indicate the direction which each pulse is moving.
Part V: Boundary Behavior
Consider the following diagram. A pulse is shown incident upon a boundary between two medium. The numbers indicate the relative rigidity of the two media. Study the diagram and answer the accompanying questions.
Part VI: Zingers/Extra Credit:
1. Two boats are anchored 4 meters apart. They bob up and down every 3 seconds, but when one is up the other is down. There are never any wave crests between the boats. Calculate the velocity of the waves.
2. A boat 4 m long is anchored facing into the waves. The waves have a velocity of 5 m/sec. It is possible for exactly three wave crests to fit under the boat at one time.
© Tom Henderson, 1996-1998
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