[填空题]
A laser beam is directed at th7i c4z kx4/tsjo .kat. ft7v6me Moon, 380 3 ttv( mq,ygc*dzvs00,000 km from Earth. The beam diverges at an c0yz*qs t ,vt(d3vm0gangle $\theta$ (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
