  The influence of the force of the quadratic resistance of the medium on the
change in some interesting characteristics of the motion of the projectile,
which take place when the projectile moves in vacuum, is investigated. Loci
that ensure maximization of the flight range, the arc length of the projectile
trajectory and a non-decreasing of the length of the radius-vector are
constructed numerically (and partly analytically). As examples, the motion of a
baseball, a tennis ball and a badminton shuttlecock is studied.
