Answer
a). No, since there is no relative velocity between the observer and the source.
There is no Doppler effect if a sound source and an observer are moving with same velocity. i.e. there is no relative velocity.
b). An increasing frequency is heard because the source is moving towards the observer, and its speed is increasing.
Work Step by Step
a). No, since there is no relative velocity between the observer and the source.
There is no Doppler effect if a sound source and an observer are moving with same velocity. i.e. there is no relative velocity.
b). An increasing frequency is heard because the source is moving towards the observer, and its speed is increasing.
