waves Flashcards
The graph below shows an oscillator undergoing Simple Harmonic Motion. Which point(s) on the graph corresponds to the oscillator having zero speed? (Click all that apply)
2, 4
A mass is bobbing up and down on a spring. If you increase the amplitude of the motion, how does this affect the time for one oscillation?
the time does not change
A mass on a spring in SHM has amplitude A and period T. How long does it take for the mass to travel a total distance of 8A?
2T
Consider a wave on a string moving to the right, as shown below. What is the direction of the velocity of a particle at the point labeled B?
upward
What is the wave speed of the wave traveling on the string? Give your answer in m/s, but do not include units with your response. Figure 1. Wave on a String at a fixed time t = 0 s. Figure 2. Wave on a String at a fixed position x = 0 m
v = wavelength/ period = 5m/2s = 2.5m/s
What might this be?
An Aeolian harp
The length of the string is 2.0 m. Approximately what is the wavelength of the two traveling waves that make up the standing wave?
wavelength/ # of loops = 2L/n / 5 = 0.4 m
A string of length 2.0 m has a mass of 125 mg. The string is attached to the ceiling and a large rock of mass 4.0 kg hangs from the other end. The rock is hit sideways with as a result, a transverse pulse travels up the string toward the ceiling. At what speed does the pulse travel?
790 m/s
A string is attached to a vibrator driven at 1.20 × 102 Hz. A weight hangs from the other end of the string; the weight is adjusted until a standing wave is formed. If the weight of the mass is 0.3 N and the linear density of the string is 0.01 Kg/m. What is the wavelength of the standing wave on the string? (It’s a real long string)
22 m
Resonance is from a Latin noun that means
an echo
Compared to sound frequency, earthquake frequencies are
much lower
If the frequency of an earthquake is 4 Hz, and the wavelength is 1500 m, what is the speed of the earthquake?
4 * 1500 = 6000 m/s
Sound waves are
-longitudinal waves characterized by the displacement of air molecules.
-longitudinal waves characterized by pressure differences.
Calculate the speed of sound at 10o C,
331.5 + (0.6 * 10) = 337.5 m/s
You have two tuning forks, one with a frequency of 235 Hz, and a second with a frequency of 236 Hz. If you hit them both at the same time, what is the beat frequency heard?
1 Hz
If the speed of sound in water is 767m/s. Caclulate the wavelength of a sound wave in water that has a frequency of 440 Hz (That’s an A) The answer should be in meters, do include the m
1.74m
A single cricket in a field is chirping at a sound level of 30 dB. What is the resulting sound level if 100 similar crickets make a chorus of chirping? Give your answer in dB.
I100/I1=100
β2−β1=10dB∗log(I2/I1)
β100−β1=10dB∗log(I100/I1)=10dB∗log(100)=20dB
50dB (Answer)
Every vibration gives the sound box a push. A frequency of 256 pushes per second is
middle C
Which of the following best describes a sound level of intensity 0.0001 W/m2?
about that of a power mower
What is the approximate decibel level of a jet engine from 30 meters?
110 dB
