[填空题]
A laser beam is directed at ti( sz6dsi0i9 she Moon, 380,000 km from Earth. The beam die5:fjzh51,ril;zx;e pchd3o verges at zz; 3c:5io pl5dx1;fhh,jere 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
