PhysLink.com Logo

Question

What speed defines Mach 1? and why?
Asked by: Anthony Matarazzo

Answer

Mach number is a common 'ratio' unit of speed when one is talking about aircrafts. By definition, Mach number is a ratio of the speed of a body (aircraft) to the speed of sound in the undisturbed medium through which the body is traveling. It is said that the aircraft is flying at Mach 1 if its speed is equal to the speed of sound in air (which is 332 m/s or 1195 km/hr or 717 miles/hour.) An aircraft flying at Mach 2 is flying at twice the speed of sound in air, etc.

Mach numbers are named after Ernst Mach (1838-1916), an Austrian philosopher and physicist. The term Mach number came into use in 1929.
Answered by: Anton Skorucak, M.S. Physics, PhysLink.com Creator


Science Quote

'An expert is someone who knows some of the worst mistakes that can be made in his subject and how to avoid them.'

Werner Heisenberg
(1901-1976)


All rights reserved. © Copyright '1995-'2016 PhysLink.com