[填空题]
A laser beam is directed atqje( 0+ rp3*onwwtxb7 the Moon, 380,000 km from Earth. The nw nhxc3p 2xv7g,dfi rb2/:* ebeam diverges at a g3dvfe7n:, n/rhp iwx2*2b cxn 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
