Principles of Flight Quiz 2

Question 1) Induced drag:

Increases as airspeed increases

Decreases as airspeed increases

Is unaffected by changes in airspeed

Decreases as airspeed decreases

Correct! Wrong!

Induced drag is inversely proportional to speed so as airspeed increases, induced drag decreases.

Question 2) The airspeed of an aeroplane in straight and level flight is increased:

Induced drag increases and parasite drag decreases

Both induced drag and parasite drag increase

Both induced drag and parasite drag decrease

Induced drag decreases and parasite drag increases

Correct! Wrong!

Parasite drag is proportional to airspeed and induced drag is inversely proportional to airspeed.

Question 3) The purpose of streamlining is to:

Delay airflow separation and reduce induced drag

Delay airflow separation and reduce form drag

Promote airflow separation and reduce parasite drag

Promote airflow separation and increase lift

Correct! Wrong!

The purpose of streamlining is to delay airflow separation and to reduce form drag. Form drag is a type of parasite drag that is affected by the shape of an object going through the air and therefore proportional to speed. Streamlining decreases form drag.

Question 4) In steady straight and level flight:

Drag is balanced by lift

Drag is balanced by thrust

Weight is balanced by thrust

Thrust is balanced by lift

Correct! Wrong!

There are two couples of forces acting on a plane lift is counteracted by weight and thrust is counteracted by drag.