Answer :
The stagnation pressure of this air is D. 73.4 kPa.
To find the stagnation pressure, we can use the formula:
P0 = P + (1/2) * ρ * V²
Where P0 is the stagnation pressure, P is the static pressure, ρ is the density of air, and V is the velocity of the air.
We are given the static pressure P as 20 kPa and the Mach number as 1.5. We can use the formula for Mach number:
Mach number = V / a
Where a is the speed of sound in air. For simplicity, we can assume that the air is at standard conditions, where a = 340 m/s.
So, 1.5 = V / 340
V = 1.5 * 340 = 510 m/s
Next, we need to find the density of air at this condition. We can use the formula:
ρ = P / (R * T)
Where ρ is the density, P is the pressure, R is the gas constant for air (287 J/kg*K), and T is the temperature. Again, assuming standard conditions, T = 273 K.
ρ = 20,000 / (287 * 273) = 0.269 kg/m³
Now we can plug in these values to find the stagnation pressure:
P0 = 20,000 + (1/2) * 0.269 * 510²
P0 = 73,360 Pa or 73.4 kPa (rounded to 3 significant figures)
Therefore, the answer is (D) 73.4 kPa.
Learn more about pressure on:
https://brainly.com/question/28012687
#SPJ11
