A train moves towards a stationary observer with speed 34 m/s. The train sounds a whistle and its frequency registered by the observe is f_1. If the train'sspeed is reduced to 17 m/s, the frequency registered is f_2 If the speed of sound is 340 m/s, then find the ratio f_1//f_2 .

A train moves towards a stationary observer with speed 34 m/s. The tra

1.	A train moves towards a stationary observer with speed 34 m/s. The train sounds a whistle and its frequency registered by the observe is f_1. If the train'sspeed is reduced to 17 m/s, the frequency registered is f_2 If the speed of sound is 340 m/s, then find the ratio f_1//f_2 .
Answer» SOLUTION :For the stationary observer `f_1 = V/(v-v_s)xxf` `:. F_1 = 340/(340 - 34) xx F and f_2 = 340/(340-17) xx f` Hence `f_2/f_1 = (340-17)/(340-34)= 19/18 rArr f_1 : f_2= 19 : 18`