Which type of drag increases as airspeed increases, and which increases as airspeed decreases?
AParasite drag increases with airspeed; induced drag increases as airspeed decreases.✓
BInduced drag increases with airspeed; parasite drag increases as airspeed decreases.
CBoth types increase and decrease together with airspeed changes.
Why →Parasite drag (form drag, skin friction, interference drag) increases with the square of velocity. Doubling speed quadruples it. Induced drag is a byproduct of lift production and increases at lower speeds when higher AOA is needed. Total drag has a U-shaped curve: high at low speed (induced dominated), minimum at best L/D speed, rising at high speed (parasite dominated).
Field note →For fixed-wing UAS, the minimum drag speed is the maximum-range speed: every knot above or below it costs energy.
SOURCE → PHAK Chapter 5, Aerodynamics of FlightCHECKED JUL 16ACS IV.A.K1MED