[填空题]
A laser beam is directed at the Moon, 380,000 km from Eart 6gj8/3iul 6xr xaqaj013;uw+n2fp cuepl7jj b 6f d7kh. The beam diverges at a1lwpuu ckpbed jj2 73;f6n+ f7n 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
