N-UNCOUNT 马赫(速度单位,1马赫等于1倍音速)Mach is used as a unit of measurement in stating the speed of a moving object in relation to the speed of sound. For example, if an aircraft is travelling at Mach 1, it is travelling at exactly the speed of sound. 马赫(速度单位,1马赫等于1倍音速) [technical]
The hot air permitted higher speeds before the critical Mach number was exceeded.
热空气可使之在超过临界马赫数之前达到更快的速度。
The aim is to fly at about Mach 2, twice the speed of sound.