3 4 c m
40cm
actual image size: 32cm x 26cm
Description
This device is used to measure the velocity of an aircraft relative to the speed of sound. Mach 1 is reached when an aircraft attains a speed of 331 metres (1087 feet) per second and thereby 'breaks the sound barrier'. The exact speed varies with altitude. The sound barrier was first broken by the American Bell X-1 aircraft piloted by Chuck Yeagher in 1947.
Image Details
Image Ref.
10216186
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