[填空题]
A laser beam is directed at t31lwh9 sv3,eoz5rz hzhe Moon, 380,000 km from Earth. The beam d qpm9j gsjw)886igfkd3d.u g4iverges at an angl3gd6)9 pqgj8u wsjd8.mkg4 f ie $\theta$ (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
