[填空题]
A laser beam is directed at the Moonpwphm i5kl471c zf:r-, 380,000 km fr:cc)yuf afnf jn3 o;hy o6t)8,om Earth. The beam diverges at an angle ,fon; jy6tc h83c u:f)foya)n$\theta$ (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
