[填空题]
A laser beam is directed au0bus71 ts ,iruwy ;.**c25dap wckc mh+/v iyt the 4lldgu. ;rhr:sd9on/Moon, 380,000 km from Earth. The beam diverges at an hl udr/.n r9o:l;g4sdangle $\theta$ (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
