[填空题]
A laser beam is directe 76fy)s-f3ix * dqum*vlgekoh0ua +r( d at the Moon, 38f9hlg8ws u(kjglr f(9q8/d- z0,000 km from Earth. The beam diverges at ((lwsg/ug dzqh9 8lf k98 jr-fan 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
