[填空题]
A laser beam is directed at thfce/ol)*sq0pcg hn+ .e zf x*pu;,7 bzpl cn/(oMoon, 380,000 km from Earth. The beam diverges at an apfboul x7zp/c*(;z , nngle $\theta$ (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
