Afinite wing area of 1.5 ft2 and aspect ratio of 6 is tested in a subsonic wind tunnel at a velocity of 180 ft/s at standard sea-level conditions. at an angle of attack of −1°, the measured lift and drag are 0 and 0.181 lb, respectively. at an angle of attack of 2°, the lift and drag are measured as 5.0 and 0.23 lb, respectively. calculate the span efficiency factor and the infinite-wing lift slope.

Lift slope = 0.55/deg

Span efficiency factor = 1.72 Am

Explanation:

S = 1.5

AR = 6

V = 180

∝ = -1    L = 0    D= 0.181

∝ = 2    L = 5    D = 0.23

Cd =

∝ = 2

Cl =  

Cd =  

Cd =

0.00399 = 0.00314 +  

e = 1.72 Am

Lift slope = a =

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