[填空题]
A laser beam is directeet p dzh.o(u(w0 y *sv,2k7v rpue/;rrd at the Moon, 380,000 km from E-rduv 5 sn(/4oxbi* fc:cpg2t arth. The beam diverges at an ad u(ivf4-px2: rg*cbc5no s/ tngle $\theta$ (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
