(a)[3]
State the SI base units for $K$.
(b)
A ball with weight $1.5\,\text{N}$ is dropped vertically from rest in air. The drag force $F_D$ acting on the ball is given by the expression in (a). The ball attains a steady (terminal) speed of $33\,\text{m s}^{-1}$. Take the upthrust on the ball to be negligible and the air density to be uniform. At the instant when the ball is moving at $25\,\text{m s}^{-1}$, determine:
(b(i))[2]
the ball’s drag force $F_D$.
(b(ii))[2]
the ball’s acceleration.
(c)[3]
Describe how the acceleration of the ball in (b) changes as its speed increases from zero to $33\,\text{m s}^{-1}$.