Question

2. The Azadi tower is the symbol of 3. The Shanghai skyline is in 4. People cycling to work in 5. The Oriental Pearl tower is in 6. River Buriganga is in 7. is a busy financial centre. 8. 'Chaikhanas' (teahouses) are found all over 9. In 2004 tsunami caused widespread damage. 10. Mount Fiji in is famous for having a perfect cone shape​

Answer 1

Answer:

or the stationary observer: 

Frequency of the sound produced by the whistle, v=400Hz

Speed of sound =340m/s

Velocity of the wind, v=10m/s

As there is no relative motion between the source and the observer, the frequency of the sound heard by the observer will be the same as that produced by the source, i.e., 400Hz.

The wind is blowing toward the observer. Hence, the effective speed of the sound increases by 10 units, i.e.,

Effective speed of the sound, ve=340+10=350m/s

The wavelength (λ) of the sound heard by the observer is given by the relation:

λ=ve/v=350/400=0.875m

For the running observer:

Velocity of the observer, vo=10m/s

The observer is moving toward the source. As a result of the relative motions of the source and the observer, there is a change in frequency (v′).

This is given by the relation:

v′=(vv+vo)v

    =(340340+10)×400=411.76Hz

Since the air is still, the effective speed of sound =340+0=340m/s

The source is at rest. Hence, the wavelength of the sound will not change, i.e., λ remains 0.875 m.

Hence, the given two situations are not exactly identical.