[填空题]
A laser beam is directed at th k0q. jhs rkl9(u7lnn4e Moon, 380,000 km f62a d..k.gaue dxz7h dl:ydw .rom Earth. The beam diverges at an angle:dghwl. d.d7e auak6 z2 .xy.d $\theta$ (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
