Answer: The correct answer is "the pitch drops to a lower pitch once the ambulance passes by Juan".
Explanation:
Doppler effect is the phenomenon in which there is an increase or decrease in the frequency when there is relative motion between the source and listener.
Pitch depends on the frequency. if the frequency increases then pitch increases.
When the source and the listener are moving towards each other then there is increase in the frequency. When the source and the listener are moving away each other then there is decrease in the frequency.
In the given problem, Juan is standing on the street. An ambulance moves toward him and then passes by the pitch drops to a lower pitch once the ambulance passes by Juan.
Answer:
(a)
(b)
(c) 
Explanation:
According to the Wein's displacement law
Where, T be the absolute temperature and b is the Wein's displacement constant.
b = 2.898 x 10^-3 m-K
(a) T = 37°C = 37 + 273 = 310 K
(b) T = 1500°C = 1500 + 273 = 1773 K
(c) T = 5800 K
The characteristic of sound that would best explain the series of echoes you are hearing would be reverberation. It is created when a sound wave is being reflected to the surfaces causing it to have a many reflection building up and decaying as these waves are being absorbed bu the surfaces in the area which could be tables, chairs, people or the air. Reverberation is the group of the reflected sounds in an enclosed area.
