16.885J/ESD. 35J-Sept 2003 LD Definitions Resultant force on body resolved into Lift l and drag d By definition, L is perpendicular to relative wine Relative wind D is parallel to relative wind16.885J/ESD.35J - Sept 2003 L, D Definitions • Resultant force on body resolved into Lift L and Drag D • By definition, – L is perpendicular to relative wind – D is parallel to relative wind c/4 V 8 α L D Relative wind