[填空题]
A laser beam is directed at the Moon, 3o tq3v8a7 fv:9 eaxnu880,000 km frgdpl9;vr)c ac(z1j 0k om Earth. The beam diverges at an an ;vdg)1kzj9(p c racl0gle $\theta$ (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
