Increased shipping represents a global threat to marine life. A phenomenon known as the bow null-effect can cause acoustic shadows around ships effectively masking their engine noise in some directions. A Dolphin swimming horizontally at a velocity of 3.50 m/s near the surface of the ocean tracks a prey fish by emitting a 55.0 kHz series of click-like sound. The sound reflects from the bow of a ship directly in front of the Dolphin. The ship is moving at a velocity of 11.5 m/s on an intercept course with the oncoming Dolphin. The speed of sound in sea water is approximately 1530m/s. Find: a) the wavelength of the sound emitte
Properties of sound
A sound wave is a mechanical wave (or mechanical vibration) that transit through media such as gas (air), liquid (water), and solid (wood).
Quality Of Sound
A sound or a sound wave is defined as the energy produced due to the vibrations of particles in a medium. When any medium produces a disturbance or vibrations, it causes a movement in the air particles which produces sound waves. Molecules in the air vibrate about a certain average position and create compressions and rarefactions. This is called pitch which is defined as the frequency of sound. The frequency is defined as the number of oscillations in pressure per second.
Categories of Sound Wave
People perceive sound in different ways, like a medico student takes sound as vibration produced by objects reaching the human eardrum. A physicist perceives sound as vibration produced by an object, which produces disturbances in nearby air molecules that travel further. Both of them describe it as vibration generated by an object, the difference is one talks about how it is received and other deals with how it travels and propagates across various mediums.
Increased shipping represents a global threat to marine life. A phenomenon known as the bow null-effect can cause acoustic shadows around ships effectively masking their engine noise in some directions.
A Dolphin swimming horizontally at a velocity of 3.50 m/s near the surface of the ocean tracks a prey fish by emitting a 55.0 kHz series of click-like sound. The sound reflects from the bow of a ship directly in front of the Dolphin. The ship is moving at a velocity of 11.5 m/s on an intercept course with the oncoming Dolphin. The speed of sound in sea water is approximately 1530m/s.
Find:
- a) the wavelength of the sound emitted by the Dolphin,
- b) the frequency of the reflected sound.
- c) If it takes 14.5 ms for the Dolphin to hear the sound reflected from the boat bow, how far away is the boat?
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