What frequency is received by a person watching an oncoming ambulance moving at 110 km/h and emitting a steady 880-Hz sound from its siren? The speed of sound on this day is 343 m/s. Submit Answer Tries 0/10 What frequency does she receive after the ambulance has passed?
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.
![**Doppler Effect in Action**
**Problem Statement:**
- **Scenario:** A person is observing an oncoming ambulance.
- **Ambulance Speed:** 110 km/h
- **Sound Emission Frequency:** 880 Hz
- **Speed of Sound:** 343 m/s
**Question 1:** What frequency is received by a person as the ambulance approaches?
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*Tries: 0/10*
**Question 2:** What frequency does the person receive after the ambulance has passed?
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**Description:**
This example illustrates the Doppler Effect, where the frequency of a wave changes for an observer moving relative to the wave source. When the ambulance is moving towards the observer, the frequency increases. After it passes, the frequency decreases.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F02ec4b82-5ff0-4052-a25d-a8fd5708f2e2%2F60f78131-8856-48ac-8728-0493c0c9d6f8%2Fnczudxk_processed.png&w=3840&q=75)
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