(a) Speed greater than the speed of sound
(b) Speed greater than Mach 5
(c) Speed greater than Mach 10
(d) Speed greater than Mach 20
Ans.(b)
Sol. Hypersonic speed is defined as a speed greater than Mach 5, where Mach 1 represents the speed of sound. Mach 5 corresponds to approximately 3,836 miles per hour (6,174 kilometers per hour) or 1.7 kilometers per second.
