The drag force on a plane is proportional to the density of the air. By what factor does the drag force change if a plane goes from an altitude 5.5 km to 11 km? The atmospheric pressure goes from to atm in going from 5.5 km to 11 km. Assume that the plane is at level flight and flies at the same speed.
D) 1
E) 2

Question

The drag force on a plane is proportional to the density of the air. By what factor does the drag force change if a plane goes from an altitude 5.5 km to 11 km? The atmospheric pressure goes from  to  atm in going from 5.5 km to 11 km. Assume that the plane is at level flight and flies at the same speed.
D) 1 
E) 2

Quizplus · Accepted Answer

The density of air decreases as altitude increases. From the given data, we can see that the atmospheric pressure decreases from 11eaa4be_851b_463c_9e4a_4fd1a66ad987_TB6080_11 to 11eaa4be_851b_6d4d_9e4a_f31c6cd50d28_TB6080_11 atm, which is a decrease by a factor of 2. Therefore, the density also decreases by a factor of 2. Since the drag force is proportional to the density of the air, it also decreases by a factor of 2 as the plane moves from 5.5 km to 11 km. Thus, the correct answer is B.

The Drag Force on a Plane Is Proportional to the Density