Erratum: “The ellipse in parabolic motion: An undergraduate experiment” [Am. J. Phys. 82, 354–356 (2014)]

Locus of the apices of projectile trajectories under constant drag

“…The numerical solutions to this condition shall be discussed below. Again we draw in blue dashed lines the drag-free solutions from (17) and (18).…”

“…The solution in terms of the angle could be hard to handle, but is straightforward for a particular locus: the locus formed by all the apices for initial launching angle q 0 . The cases for no drag [16][17][18] and linear drag have been studied previously [19][20][21].…”