[填空题]
A laser beam is directed at the Moon, 380,000 km fr+6+t( 4o2r:blsn; mjkzmo uulf54al/egjqvd/ c7 1ug om Earth. The beam diverges at euj5ld/ac7/1fv gqg4 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
