[填空题]
You look directly overhead and:mx s-a: /id2a.zr xiw,q9eav see a plane exactly 1.5 kt;v:+yp k:rh:1ubpycm above the ground flying faster than the speed of sound. By the:yrphvkbu;: +ptc:1y time you hear the sonic boom, the plane has traveled a horizontal distance of 2.0 km. See Fig. 12–34. Determine
(a) the angle of the shock cone, $\theta$ $^{\circ} $
(b) the speed of the plane (the Mach number). Assume the speed of sound is 330 m/s