[填空题]
A laser beam is direnz pd16:58zhuwxan3e9dxmv.cted at 4h09vb9c hn j4 (1;rujrify1 h4zldymthe Moon, 380,000 km from Earth. The beam diverges at a1u4nmh9dcl(r i944 zbvhyfy1j; j0 rh n 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
