[填空题]
A laser beam is direczgr7ue5g i rkzd7:8s9ted at the Moon, 380,000 km from Earth. ; )si,w 5 efn)enmedlf kn ek-00gv5v0The beam diverges at an angk)dkf v, v0eei0le5gmewn0-5sfn;n)le $\theta$ (Fig. 8–37) of $1.4\times10^{-5}$ rad What diameter spot will it make on the Moon? m
Post time 2025-2-18 20:00:22
