[填空题]
A laser beam is directe;.maj2nqqn u9t8dz c -d at t xdn 7 9rka7+ xolj*3qzt4cg8she Moon, 380,000 km from Earth. The beam diverges atadgjrt+8s qc3z79 lxon4k *7x an angle $\theta$ (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
