Answer:
1.36
Explanation:
= Index of refraction of air = 1
= Index of refraction of plastic = ?
i = angle of incidence in air = 32.0° deg
r = angle of refraction in plastic = 23.0° deg
Using Snell's law
Sini =
Sinr
(1) SIn32.0 = Sin23.0
= 1.36
Answer:
The correct answer is option 'd': The frequency decreases and the intensity of the sound decreases.
Explanation:
1) <u>Effect on Frequency </u>
According to Doppler's effect of sound we have
for a source of sound moving away from the observer the relation between the observed and the original frequency is given by
where
c = speed of sound in air
is the velocity of observer of sound
is the velocity of source of sound
is the original frequency of sound
As we see the ratio is less than 1 thus the frequency of sound that the observer receives is less than that of source.
2) <u>Effect on Intensity:</u>
At a distance 'r' from source emitting a wave of Power 'P' is given by
As we see on increasing 'r' intensity of sound decreases.