[填空题]
A laser beam is directecwf,s5kf je96 d at the Moon, 380, qka/h-kf,ic k 08mfg.7ivts;000 km from Earth. The beam diverges at an an.,svmq ;7g/i-ktic08 kkafhf gle $\theta$ (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
