[填空题]
A laser beam is directed at to..e zjx:dq3 ii1kd a0he Moon, 380iaeimen ni1 ,)/::pvs,000 km from Earth. The beam diverges at an1 ,v)/pn:: mineseiia 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
