A ball of weight 1.5 N falls vertically from rest in air. The drag force F D acting on the ball is
given by the expression in (a). The ball reaches a constant (terminal) speed of 33 m s–1.
Assume that the upthrust acting on the ball is negligible and that the density of the air is
uniform.
For the instant when the ball is travelling at a speed of 25 m s–1, determine
(i) the drag force F D on the ball,
FD = ...................................................... N