Which type of drag increases as airspeed increases, and which increases as airspeed decreases?
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).The trap →
The relationship is counterintuitive: drag that "fights" forward motion (parasite) worsens going faster. Drag from "making lift" (induced) worsens going slower. At their intersection is the minimum drag speed. The most efficient airspeed for range.SOURCE → PHAK Chapter 5, Aerodynamics of FlightCHECKED APR 21ACS IV.A.K1MED