Arailroad crossing warning signal sounds at 120 hz. a) if you are approaching the crossing at 3% of the speed of sound, find the frequency you would hear. b) if you were going away from the crossing at 3% of sound speed, find the observed frequency.

Answer

given,

frequency of sound (f)= 120 Hz

speed of sound (v)= 343 m/s

a) speed of approaching = 3 % of speed of sound

                          = 0.03 x 343 = 10.3 m/s

     frequency you would hear

            f' = 123.60 Hz

b)  speed of going away = 3 % of speed of sound

                          = 0.03 x 343 = 10.3 m/s

     frequency you would hear

            f' = 116.39 Hz

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s