Question

Calculate the ratio of the drag force on a jet flying at 1049 km/h at an altitude of 10.0 km to the drag force on a prop-driven transport flying at 560 km/h and at an altitude of 5.00 km. The density of air is 0.380 kg/m3 at 10.0 km and 0.670 kg/m3 at 5.00 km. Assume that the airplanes have the same effective cross-sectional area and drag coefficient C.

Answer 1

The drag force in each case is
C*(1/2)*(air density)*V^2

Ratio (jet/prop) = (0.380/0.670)*(1049/560)^2 = 1.99

Note that I did not have to change dimensions to m/s, since I used the same velocity dimensions for both planes.

Answer 2

Thank you so much... Huge help

Answer 3

It's very helpful and its explained in simple terms which makes it easier to understand.