For air flow over the wing of an airplane, which of the following definitions of Reynolds number will let you determine the drag force on the wing? Uo is the freestream velocity, L is the length of the wing in the flow direction, B is the width of the wing, x is the distance along the wing from the leading edge, and t is the thickness of the wing.
a. UoL / v
b. UoB / v
c. Uox / v
d. Uot / v