The sound produced by the siren of an ambulance would have

The Doppler effect is a phenomenon observed whenever the source of waves is moving with respect to an observer. The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for the observer and the source are approaching and an apparent downward shift in frequency when the observer and the source is receding. The Doppler effect can be observed to occur with all types of waves - most notably water waves, sound waves, and light waves. The application of this phenomenon to water waves was discussed in detail in A common Physics demonstration the use of a large Nerf ball equipped with a buzzer that produces a sound with a constant frequency. The Nerf ball is then thrown around the room. As the ball approaches you, you observe a higher pitch than when the ball is at rest. And when the ball is thrown away from you, you observe a lower pitch than when the ball is at rest. This is the Doppler effect. Explaining the Doppler Effect actual change in the frequency of the source. The source puts out the same frequency; the observer only perceives a different frequency because of the relative motion between them. The Doppler effect is a shift in the apparent or observed frequency and not a shift in the actual frequency at which the source vibrates. Shock Waves and Sonic Booms bunched up at the front of the aircraft. This phenomenon is known as a shock wave. Shock waves are also produced if the aircraft mov...

• • • • Question:An ambulance is rushing towards the scene of a multi-car accident. The ambulance is moving at 35.0 m/s on a cool day where the air temperature is only -10.0°C. The siren is blaring producing a sound wave with a frequency of 1000 Hz. 1. What is the speed of sound in air? 2. What frequency will an observer in one of the cars hear? 3. The sound wave produced by An ambulance is rushing towards the scene of a multi-car accident. The ambulance is moving at 35.0 m/s on a cool day where the air temperature is only -10.0°C. The siren is blaring producing a sound wave with a frequency of 1000 Hz. 1. What is the speed of sound in air? 2. What frequency will an observer in one of the cars hear? 3. The sound wave produced by the ambulance is reflects off one of the cars and moves back towards the ambulance. What reflected frequency will the ambulance driver hear? 4. The wind begins to blow at 10 m/s towards the ambulance. What is the new reflected frequency heard by the ambulance driver? Previous question Next question

Learning Objectives By the end of this section, you will be able to: • Explain the change in observed frequency as a moving source of sound approaches or departs from a stationary observer • Explain the change in observed frequency as an observer moves toward or away from a stationary source of sound The characteristic sound of a motorcycle buzzing by is an example of the Doppler effect. Specifically, if you are standing on a street corner and observe an ambulance with a siren sounding passing at a constant speed, you notice two characteristic changes in the sound of the siren. First, the sound increases in loudness as the ambulance approaches and decreases in loudness as it moves away, which is expected. But in addition, the high-pitched siren shifts dramatically to a lower-pitched sound. As the ambulance passes, the frequency of the sound heard by a stationary observer changes from a constant high frequency to a constant lower frequency, even though the siren is producing a constant source frequency. The closer the ambulance brushes by, the more abrupt the shift. Also, the faster the ambulance moves, the greater the shift. We also hear this characteristic shift in frequency for passing cars, airplanes, and trains. The Doppler effect is an alteration in the observed frequency of a sound due to motion of either the source or the observer. Although less familiar, this effect is easily noticed for a stationary source and moving observer. For example, if you ride a train past...

The correct option is C High pitch and large amplitude. The loudness of sound is directly proportional to the amplitude of the sound wave. So when amplitude increases, loudness of the sound also increases. The piercing nature of sound depends on the pitch of sound. For a loud and piercing sound, the siren needs to be of high pitch and large amplitude.