I believe the answer is manipulation of information. Hope I helped!
Sound source is at rest, you are moving with velocity v, f = frequency, c = speed of sound:
f = f0(1 + v/c)
115 = 100(1 + v/343)
115 = 100 + 100v/343
15 = 100v/343
v = 15*343/100
<span>
v = 51,45 m/s </span>
Nothing happens to the mirror.
However, if the ray is within some suitable range of
wavelengths, the ray is reflected from the mirror's surface.
