An observer and a source of sound both are moving towards a reflector with the velocities of 38 m/s and 10 m/s respectively. The source is between the observer and the reflector. The reflector also moves away from the source with a velocity 15 m/s. The frequency of the sound emitted by the source is 340 Hz and the velocity of sound in air is 330 m/s. Then choose the correct option(s).
(a) Wavelength of echo (sound reflected from the reflector) received by the observer is approximately 1.03 m
(b) The beats frequency heard by the observer is 8 Hz .
(c) Wave length of sound heard by the observer coming directly from the source is 1 m .
(d) The frequency of the echo heard by the observer is 357 Hz