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3 years ago

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As you stand near a railroad track, a train passes by at a speed of 31.7 m/s while sounding its horn at a frequency of 218 Hz. W

hat frequency do you hear as the train approaches you and what frequency while it recedes?

1 answer:

Darya [45]3 years ago

6 0

Explanation:

Given that,

Frequency of train horn, f = 218 Hz

Speed of train, $v_t = 31.7 m/s$

The speed of sound, V = 344 m/s (say)

The speed of the observed person, $V_o=0\ m/s$

(a) When the train approaches you, the Doppler's effect gives the frequency as follows :

$f'=f(\dfrac{V}{V-v_t})\\\\f'=218\times (\dfrac{344}{344-31.7})\\\\f'=240.12\ Hz$

(b) When the train moves away from you, the Doppler's effect gives the frequency as follows :

$f'=f(\dfrac{V}{V+v_t})\\\\f'=218\times (\dfrac{344}{344+31.7})\\\\f'=199.6\ Hz$

Hence, this is the required solution.

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a) Not Accurate

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c) Accurate

d) Accurate

Explanation:

Part a

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Answer:

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In a L C R circuit, the average power is given by

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As given in the question

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So

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Using properties of logarithms we have,

$\frac{17}{10} = log_{10} \frac{I}{I_0}$

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Incomplete question. Missing part:

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