10. Who was the first person to break the sound barrier?
From Quiz Famous Firsts
Answer:
Charles Elwood Yeager
Chuck Yeager was the first person to break the sound barrier. On October 14, 1947, while flying the experimental Bell X-1, he hit mach 1.07 at an altitude of 13,700m (45,000 ft). Yeager accomplished this event over the skies of Muroc Air Force Base, California. Interestingly, Yeager was able to break the sound barrier while nursing two broken ribs (when he fell off a horse two days earlier), having a broom handle as an extra lever to close the aircraft door secure (as he was in so much pain he couldn't close it unassisted); and shampoo rubbed over the canopy of the aircraft. To prevent the windshield from frosting over, Yeager's crew chief, Jack Russell, rubbed the rocket aircraft's canopy with Drene shampoo.
Mach 1, the speed of sound, is 758 mph (1,220 kph) at sea level. It decreases with altitude.