Calculating the speed of an approaching vehicle given the frequency of a car horn.

A student in a parked car honks the horn, which has a `proper' frequency of 300 Hz. An observer in an approaching vehicle measures the frequency of the sound to be 329 Hz. Calculate the speed of the approaching vehicle. Use 343 m/s as the speed of sound in air.

Working with velocity equations in a mechanical energy question.

The height of the upper falls at Yellowstone Falls is 33.2 m. When the water reaches the bottom of the falls, its speed is 25.8 m/s. Neglecting air resistance, what is the speed of the water at the top of the falls?

microphone in ocean

A microphone in the ocean is sensitive to sounds emitted by porpoises. To produce a usable signal, sound waves striking the microphone must have an intensity of 10.7 dB. If porpoises emit sound waves with a power of 0.0491 W, how far can a porpoise be from the microphone and still be heard? Disregard absorption of sound waves by ...continues

Working with sound intensities.

A person standing a certain distance from an airplane with three equally noisy jet engines is feeling a sound level intensity bordering on pain, 120 dB. What sound level intensity (in dB) would this person experience if the captain shut down one engine?

guitar string

A particular guitar string is supposed to vibrate at 199.1 Hz, but it is measured to actually vibrate at 214.2 Hz. By what percent should the tension in the string be changed to cause the string to vibrate at the correct fundamental frequency? [Enter the percentage only; do not enter units.]

spring

A 69.3 kg person jumps from a window to a fire net 21.8 m below, which stretches the net 1.20 m. Assume that the net behaves like a simple spring, and calculate how much it would stretch if the same person were lying in it.

Determining the type of interference from the given situation.

A person stands between two speakers driven by the same source. Each speaker produces a tone with a frequency of 200 Hz on a day when the speed of sound is 330 m/s. The person is 1.65 m from one speaker and 4.95 m from the other. What type of interference does the person sense? a: constructive b: destructive c ...continues

Moment of Inertia of a thin uniform rod by integration

A thin, uniform rod has length L and mass M. a. Find by integration its moment of inertia about an axis perpendicular to the rod at one end. b. Find by integration its moment of inertia about an axis perpencicular to the rod at its center of mass.

True and false questions about sound wave, frequency and intensity.

Consider two sources of sound, each of which emits a sound wave of the SAME frequency and the SAME intensity. The sources are located on a straight road, relatively close to each other. You (the listener) are also located on the same road, about 1/4 mile away. All 3 objects (source A, source B and you) are in a straight line. Wh ...continues

True and false questions about a stretched string and standing waves.

A string of length L is stretched horizontally between two fixed points. When the string is plucked vertically, standing waves can be formed on the string. Which of the following statements are true about this situation? (Give ALL correct answers) A) It is possible for half a wavelength to fill the length of the string B) ...continues