i$)$ A $20\mathrm{.}0kg$ box of goods is thrown directly downwards from a height of $3\mathrm{.}00m,$ with an initial speed of $2\mathrm{.}00\frac{m}{s}.$ The air drag on the box is negligible. Calculate $($a$)$ the kinetic energy of the box as it reaches the ground at the end of its fall and when it is halfway to the ground.

$($b$)$

Calculate the speed of the box $0\mathrm{.}200s$ before it reaches the ground.