[填空题]
A laser beam is direyj clqpacad4l t c.)wxtb:+4:71w 1raz 96f ltcted at the h60c)-xyi pxnp+ t8bh Moon, 380,000 km from Earth. The beam diverges at an angicbx60h- 8pnt )yh+ pxle $\theta$ (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
