How many MPH is mach 1?

Question

How many MPH is mach 1?

Answer 1

The speed of sound.  It is about 740 mph at sea level.  It slows down with altitude.  The closer, or more dense, the air molecules, the faster the sound wave can travel.  That is why sound goes through water and solids faster than it goes through air, because the molecules in water or solid are more dense, closer together, than is air.  It is easier for the molecules to react against each other when they are closer together, thus faster travelling sound waves.

Answer 2

The speed of sound, mach 1, in air, is 769MPH

Answer 3

MACH 1 is the speed of sound.

However, the speed of sound is not a fixed figure (unlike the speed of light). The speed of sound depends upon the matter through which travel is being undertaken, the temperature and the pressure.

It is therefore impossible to answer your question - sorry.

Answer 4

From Wikipedia:

Since the speed of sound increases as the temperature increases, the actual speed of an object travelling at Mach 1 will depend on the fluid temperature around it. Mach number is useful because the fluid behaves in a similar way at the same Mach number. So, an aircraft travelling at Mach 1 at sea level (340.3 m/s, 1,225.08 km/h) will experience shock waves in much the same manner as when it is travelling at Mach 1 at 11,000 m (36,000 ft), even though it is travelling at 295 m/s (654.632 mph, 1,062 km/h, 86% of its speed at sea level).

From NASA:

The Mach number depends on the speed of sound in the gas and the speed of sound depends on the type of gas and the temperature of the gas. The speed of sound varies from planet to planet. On Earth, the atmosphere is composed of mostly diatomic nitrogen and oxygen, and the temperature depends on the altitude in a rather complex way. Scientists and engineers have created a mathematical model of the atmosphere to help them account for the changing effects of temperature with altitude. Mars also has an atmosphere composed of mostly carbon dioxide. There is a similar mathematical model of the Martian atmosphere. We have created an atmospheric calculator to let you study the variation of sound speed with planet and altitude.

The nasa site has a calculator to determine actual Mach speeds...

Aerospace website has a handy chart for determining Mach speeds...

Answer 5

The standard atmospheric model tells us that the speed of sound, or Mach 1, at sea level is:

1,116.4 ft/s

340.3 m/s

761.2 mph

1,225.1 km/h

661.5 knots

Answer 6

Depends on altitude and humidity. Roughly 720 mph +-