Answer:
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
[tex]\varphi = 0.38428 \ kg/m^3[/tex]
The velocity is also given as: 550 mph = 245.872 m/s
Therefore, the sonic velocity is firstly determined by using the formula:
[tex]a = \sqrt{ \vartheta \times R \times T\[/tex]
[tex]a = \sqrt{1.4 \times 287 \times 323.78176[/tex]
[tex]a = \sqrt{130095.5112[/tex]
a = 360.68755 m/s
Then, we can calculate the Mach number by using the expression:
[tex]{Mach \ number = \dfrac{V}{a}}[/tex]
[tex]Mach \ number = \dfrac{245.872}{360.68755}[/tex]
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.
Before you calculate the moment capacity for a steel beam, you have to determine the classification of beam.
a. True
b. False
Answer:
True
Explanation:
True - because different classification of steel beam have different yield strength.
The moment capacity for a steel beam is given by;
M = Mn / Ωₙ
where;
M - the maximum moment acting on the beam
Ωₙ - is the Safety Factor for Elements in Bending = 1.67
Mn - nominal moment of the steel, given as
[tex]M_n = Z_x *f_y[/tex]
where;
Zₓ - the Plastic Section Modulus in the x or strong axis.
[tex]f_y -[/tex] is the Yield Strength of the Steel (A36W, A46 W or A50W)
A36W = 36 ksi
A46 W = 46 ksi
A50W = 50 ksi
Thus, before you calculate the moment capacity for a steel beam, you have to determine the classification of beam, for the yield strength of the steel beam.