[填空题]
A laser beam is dire gvii68.g2xget7ub1 r2;vk dt40 6gdqc:gomhc23hbt cted at the Moon, 380,000 km from Earth. The beam diverges amc;chhbqg36g:o2dk2 t dv4t0 t 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
