الحل الاول:
one revolution = time of the light to make one round trip between the mirrors*1/8
1/8-------------------------------------------------------------------------70km
32000------------------------------------------------------------------------------x
x=17.92*10^6km
f=x/t=32000/60=533.33Hz
wave length=x/n=17.92*10^6/32000=560km
velocity=533.33*560*10^3=2.99*10^8m/s
بلييييز حد يرد يقول صح ولا لأ