[填空题]
A laser beam is directedr8 p mw)/osi 7ly(1 rb608ne+tvrfgof at the Moon, 380,000 km from Earth. Th+aa pc 1uzng9*qbd e( ;fty b96f,dnu0e beam diverges at an angle1ez (a* nf,6ynuf ;p0 qddua99bc+bgt $\theta$ (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
