[填空题]
The Near Earth Asterned): h vqc0c: nosb).-8aw uxoid fey0aysb 4ye s9s(( x lfi5*0wRendezvous (NEAR), after traveling 2.1 billion km, is meant to orbit the asteroid Eros at a height of about 15 km . Eros is rough5y*li es090faw yb4e(s (xsfy ly 40 $\mathrm{~km} \times 6 \mathrm{~km} \times 6 \mathrm{~km}$ . Assume Eros has a density (mass/volume) of about 2.3 $\times 10^{3} \mathrm{~kg} / \mathrm{m}^{3}$ . (a) What will be the period of NEAR as it orbits Eros? $\approx$ $\times 10^4$sec
(b) If Eros were a sphere with the same mass and density, what would its radius be? $\approx$ $\times 10^3$
(c) What would g be at the surface of this spherical Eros?$\approx$ $\times 10^{-3}$
