他们的计算表明，快速而持续的微小空气波动可以使毯子达到每秒一英尺(译者：30.48厘米)的飞行速度。
Their calculations showed that small waves of air in repeated fast pulses could steer a carpet at a speed of around one foot per second.
如若这样，那么3千3百万焦耳发射出的炮弹速度高达每秒5500英尺，这一速度超越了音速，会产生音爆。
In this case, the 33 megajoules launched the shot 5,500 feet per second, exceeding the speed of sound and releasing a sonic boom.
如若这样，那么3千3百万焦耳发射出的炮弹速度高达每秒5500英尺，这一速度超越了音速，会产生音爆。
In this case, the 33 megajoules launched the shot 5, 500 feet per second, exceeding the speed of sound and releasing a sonic boom.
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