Respuesta :
1) Velocity of the sound wave at 20°C: 343 m/s
2) Velocity of the sound wave at 18°C: 341.8 m/s
3) a. decrease b. increase c. not change d. decrease
4) Constructive and destructive interference (see description)
Explanation:
1)
The velocity of a sound wave as a function of the temperature of the air is given by the equation
[tex]v(T) = 331 + 0.6T[/tex]
where
v is the velocity
T is the temperature, measured in Celsius degrees
In this problem, we want to calculate the velocity of the sound wave when the temperature is
[tex]T=20^{\circ}C[/tex]
Substituting into the equation, we find:
[tex]v=331+0.6\cdot 20=343 m/s[/tex]
2)
In order to solve this problem, we can use the same equation used in the previous problem:
[tex]v(T) = 331 + 0.6T[/tex]
where T is the temperature measured in Celsius degrees.
In this problem, the temperature is
[tex]T=18^{\circ}C[/tex]
Therefore, the velocity of the sound wave in this case is
[tex]v=331+0.6\cdot 18=341.8 m/s[/tex]
3)
Let's analyze each situation:
a. Lowering the humidity of the air --> This will result in a decrease of the speed of sound. In fact, as the humidity of the air decreases, the percentage of molecules of water in the air decreases too. We also know that sound travels faster in water than in air: therefore, if there are less molecules of water, the speed of a sound wave will be lower as well.
b. Increasing the temperature of the air --> This will result in an increase of the speed of sound, for the opposite reason.
c. Leaving the density of the air constant --> This will not change the speed of sound. The speed of sound depends on the density of the air: but if the density does not change, then the speed of sound will not change either.
d. Changing the direction of the wind so that it’s blowing in the opposite direction of the sound wave --> This will result in a decrease of the speed of sound. Since the wind is blowing in the opposite direction of the sound wave, particles are "pushed" back in their motion, therefore the overall velocity of the wave will be lower.
4.
Two types of interference can occur when two waves meet:
- Constructive interference: this type of interference occurs when the two waves, having same frequency, meet and they are in phase. In this case, the amplitude of the resultant wave is the sum of the amplitudes of the individual waves (reinforcement)
- Destructive interference: this type of interference occurs when the two waves meet and they are in opposite phase. In this case, the crest of a wave cancels out with the trough of the other wave, and therefore the overall amplitude of the resultant wave is zero.
Learn more about sound waves:
brainly.com/question/4899681
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Answer:
1. v = 331 m/s + (0.6 m/s/C) × T
v = 331 m/s + (0.6 m/s/C) × 20°C
v = 331 + 0.6 × 20
v = 331 + 12
v = 343 m/s
2. v = 331 m/s + (0.6 m/s/C) × T
v = 331 m/s + (0.6 m/s/C) × 18°C
v = 331 + 0.6 × 18
v = 331 + 10.8
v = 341.8 m/s
3. a. Decrease
b. Increase
c. Not change
d. Decrease
4. If component waves have the same amplitude and same frequency, are in phase, and travel in the same direction, reinforcement occurs. The resultant wave travels in the same direction as each component wave and is in phase with the component waves. It has the same frequency and same wavelength, but the amplitude is twice as great as the amplitude of either component wave. If the two waves are out of phase and are moving molecules through the same distance in opposite directions, the resultant motion is zero. Here interference occurs.
Reinforcement and interference can occur within a resultant wave that results from waves with different frequencies.
Explanation:
