[填空题]
A laser beam is directed at the Moon, 380,000 km from Earth. The beam epmt8n1h.c tz-.ssp; diverges.ix q pkfzsb, j;4td-) at an aq,zbtx -pfi);ks4jd. ngle $\theta$ (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
