A train is traveling at 30.0m/s relative to the ground in still air. The frequen
ID: 1909156 • Letter: A
Question
A train is traveling at 30.0m/s relative to the ground in still air. The frequency of the note emitted by the train whistle is 262Hz . The speed of sound in air should be taken as 344m/s . Part A What frequency is heard by a passenger on a train moving at a speed of 18.0m/s relative to the ground in a direction opposite to the first train and approaching it? Express your answer in hertz. Part B What frequency is heard by a passenger on a train moving at a speed of 18.0m/s relative to the ground in a direction opposite to the first train and receding from it? Express your answer in hertz.Explanation / Answer
a)fL =fs[(Vs+VL)/(V-Vs)]
fL=262[(344+18)/(344-30) =302HZ
b)fL =fs[(Vs-VL)/(V+Vs)]
fL=262[(344-18)/(344+30) =228.4HZ