[填空题]
You look directly overhead and see a plane b/r9n9s;u*d 1hrrc1p qcj (cnexactly 1.5 km above2qyokz63 mo2 gzl;j.b the ground flying faster than the speed of sound. By the time you hear the sonic boom, the plane has traveled a horz3j ol6ozkb;2 mg2.yqizontal 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