A high-flying Concorde passenger jet displays its Mach number on a screen, cruising at 3000 km/h to be 2.8?

Question

What is the speed of sound at that altitude?

help help!

i have already found a:

(a) How fast is an object moving on land if it is moving at Mach 0.27?

92.5 m/s

Answer 1

Seems to be a straight forward arithmetics problem. The speed of sound is 3000/2.8 = 1071.43 km/h.

This relates to a speed of 297.62 m/s. Unfortunately this speed is at an altitude of 24 km, way above the Concorde's service ceiling and the speed is beyond the Concorde's capabilities.

So in the practical world, the question uses exaggerated conditions, but the arithmetical answer is valid.

Answer 2

Concorde can't do Mach 2.8. It's cruising speed is Mach 2 and max speed is Mach 2.2

So whoever made up this question needs a reality check.

(And here's a related oops: Ministry of Education, ROC-Taiwan, have a question on their website: where is United Nations founded?  Out of the four choices, none gave the correct answer.)

Answer 3

Concorde can't fly that fast.

Answer 4

the speed of sound is depend on, k (specific heat ratio, 1.4 for air- so the media), R (universal gas constant, 287 J/kgK - again media) and the temperature (Kelvin) if SI would used.

a = square(k*R*T), so one could obtain 'a' as m/s.

increasing the altitude, decrease the temperature untill stratopause, therefore the speed of sound decrease for this range...

so your question (a) is majorly depend on temp of sea level...

not always Ma 0.27 is equal to 92.5 m/s at even land...

Answer 5

depends on the temp