[填空题]
Hurricanes can involve )3wknhn7d wm5(haftg3 hvl 5plll9 7: wind1jkv r cdf t6hg;9y2k24 od /xveio8g/s in excess of 120 $km/h$ at the outer edge. Make a crude estimate of (a) the energy, $ \times10^{16 }$ J (b) the angular momentum, of such a hurricane, approximating it as a rigidly rotating uniform cylinder of air (density 1.3 $kg \cdot m^2$) of radius 100 km and height 4.0 km. $ \times10^{20 }$ $kg \cdot m^2$