Current is measured in Amperes (usually just referred to as âAmpsâ). An ampere is defined as 6.241*10 18 electrons (1 Coulomb) per second passing through a point in a circuit. Amps are represented in equations by the letter âIâ.
The X-1, piloted by Chuck Yeager, was the first manned airplane to exceed the speed of sound in level flight and was the first of the X-planes, a series of American experimental rocket planes (and non-rocket planes) designated for testing of new technologies and often kept secret.
The first flight at faster than three times the speed of sound occurred on 27 September 1956. The aircraft was the Bell X-2 and the pilot was Captain Milburn Apt. The Bell X-2 was launched from a specially-modified Boeing B-50 at 31,800 feet. It achieved a speed of Mach 3.196 (2,094 mph).