What is the net upward force on an airplane wing of area 20 m^2 . if the speed of airflow is 300 m/s across the top of the wing and 280 m/s across the bottom? assume the Density of air is 1.29 kgm^-3 .
a. 3.5*10^4N
b. 5.5*10^7N
c.4.5*10^8N
d.1.5*10^5N
impatient much?
Once is enough, thank you.
Repeated postings will not get faster or better responses.
Hi anonymous, this isn't my question but I reposted my physics question a couple times too but I only did it because I thought it would help others see it after it wasn't answered, I'm so sorry if it came off as impatient.
To determine the net upward force on the airplane wing, we'll use the concept of Bernoulli's principle. According to Bernoulli's principle, when the speed of a fluid (in this case, air) increases, its pressure decreases, and vice versa.
First, let's find the pressure difference between the top and bottom surfaces of the wing using Bernoulli's principle. The equation is:
P + ½ρv² + ρgh = constant
Where:
P is the pressure
ρ is the density of air (given as 1.29 kg/m³)
v is the velocity of the air
g is the acceleration due to gravity (approximately 9.8 m/s²)
h is the height (assume it as constant between the top and bottom surfaces)
We'll use this formula for both the top and bottom surfaces of the wing. The only difference is the velocity of the airflow.
For the top surface:
P₁ + ½ρv₁² + ρgh = constant
For the bottom surface:
P₂ + ½ρv₂² + ρgh = constant
Since the height is the same and the pressure at the top and bottom surfaces are equal (the wing is assuming to be level), we can simplify the equation:
½ρv₁² = ½ρv₂²
Now we can calculate the net upward force (F) using the Bernoulli's principle equation:
F = (P₂ - P₁) × A
Where:
A is the area of the wing (given as 20 m²)
To find the pressure difference, let's use the equation:
½ρv₁² - ½ρv₂² = P₂ - P₁
We'll substitute the given values and solve for the pressure difference:
½ × 1.29 kg/m³ × (300 m/s)² - ½ × 1.29 kg/m³ × (280 m/s)² = P₂ - P₁
Now we have the pressure difference, we can calculate the net upward force:
F = (P₂ - P₁) × A
Finally, we'll compare the calculated force to the given options and select the correct answer.