There are 50 sportspersons in a summer sports camp. Every morning before the practice there is a compulsory warm up exercise in the ground. Sportspersons are doing their warm up in a single column and facing towards to the coach. The coach giving instruction to them from his fixed position. The distance between the coach and last sportsperson is 100 m. Once the coach whistled they dispose of their respective position. One day when the coach whistled at that time a heavy wind blowing towards the sportspersons with the velocity of 20 m/s, but nobody moved for 10 seconds. What frequency the last sportsperson heard when the whistle was blown? [The frequency of whistle is 16 kHz and velocity of sound is 340 m/s]
1. 15 kHz
2. 16 kHz
3. 17 kHz
4. 15.5 kHz
