Exam 17: Superposition

A guitar string is fixed at both ends.If you tighten it to increase its tension

A woman is riding a bicycle at 18.0 m/s along a straight road that runs parallel to and right next to some railroad tracks.She hears the whistle of a train that is behind.The frequency emitted by the train is 840 Hz,but the frequency the woman hears is 778 Hz.Take the speed of sound to be 340 m/s. (a)What is the speed of the train,and is the train traveling away from or toward the bicycle? (b)What frequency is heard by a stationary observer located between the train and the bicycle?

A 1.30-m long gas column that is open at one end and closed at the other end has a fundamental resonant frequency 80.0 Hz.What is the speed of sound in this gas?

A person is hearing two sound waves simultaneously.One has a period of 1.50 ms and the other one a period of 1.54 ms.What is the period of the beat due to these two waves?

A wave pulse traveling to the right along a thin cord reaches a discontinuity where the rope becomes thicker and heavier.What is the orientation of the reflected and transmitted pulses?

Radio station KBOB broadcasts at a frequency of 85.7 MHz on your dial using radio waves that travel at 3.00 × 10⁸ m/s.Since most of the station's audience is due south of the transmitter,the managers of KBOB don't want to waste any energy broadcasting to the east and west.They decide to build two towers,transmitting in phase at exactly the same frequency,aligned on an east-west axis.For engineering reasons,the two towers must be AT LEAST 10.0 m apart.What is the shortest distance between the towers that will eliminate all broadcast power to the east and west?

An airplane flying faster than the speed of sound of 340 m/s produces a shock wave that makes an angle of 50° with the direction the plane is flying.What is the speed of the plane?

A policeman in a stationary car measures the speed of approaching cars by means of an ultrasonic device that emits a sound with a frequency of 41.2 kHz.A car is approaching him at a speed of 33.0 m/s.The wave is reflected by the car and interferes with the emitted sound producing beats.What is the frequency of the beats? The speed of sound in air is 330 m/s.

A thin taut string is fixed at both ends and stretched along the horizontal x-axis with its left end at x = 0.It is vibrating in its third OVERTONE,and the equation for the vertical displacement of any point on the string is y(x,t)= (1.22 cm)sin[(14.4 m^-1)x] cos[(166 rad/s)t]. (a)What are the frequency and wavelength of the fundamental mode of this string? (b)How long is the string? (c)How fast do waves travel on this string?

One of the harmonics of a column of air open at one end and closed at the other has a frequency of 448 Hz and the next higher harmonic has a frequency of 576 Hz.What is the fundamental frequency of the air column?

Two harmonic sound waves reach an observer simultaneously.The observer hears the sound intensity rise and fall with a time of 0.200 s between the maximum intensity and the succeeding minimum intensity.What is the difference in frequency of the two sound waves?