A commercial jet is flying at a standard altitude of 35,000 ft with a velocity of 550 mph: (a) what is the Mach number? (b) should the flow be treated as incompressible, why or why not?

Mach number = 0.68168

The flow should be treated as compressible.

Explanation:

Given that:

The altitude of a commercial jet = 35000

The properties of air at that given altitude are as follows:

Pressure = 24.577 kPa

Temperature T = 50.78176° C

Temperature T = ( 50.78176 + 273 )K = 328.78176 K

The velocity is also given as: 550 mph = 245.872 m/s

Therefore, the sonic velocity is firstly determined by using the formula:

a = 360.68755 m/s

Then, we can calculate the Mach number by using the expression:

Mach number = 0.68168

b) Ideally, all flows are compressible because the Mach number is greater than 0.3, suppose the Mach number is lesser than 0.3, then it is incompressible.

the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true?

a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of

5

9

degree celsius.

a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.

a temperature increase of

5

9

degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.

a) i only

b) ii only

c) iii only

d) i and ii only