The pitch of a whistle of an engine appears to drop by 30 % of original value when it passes a stationary observer. If the speed of sound in air is 350 ~ms ⁻¹ , then the speed of engine in ms ⁻¹ is

Step-by-step solution

Speed of sound =350 ~m / s Also,' ....(given) n ^ = n - 30 100 n = 70 100 n =0.7 n If n is the original (actual) frequency of the whistle and n ^ the frequency as the engine passes the stationary observer, then array ll & n ^ n = ( v v + v _ cngine ) & 0.7= 350 350+ v _ engine & 0.7 y _ engine +245=350 & v _ engine =150 ~m / s array