Points: $4$

In Fig. $6\mathrm{.}1,$ a constant external force $P=130N$ is applied to a $20-kg$ box, which is on a rough horizontal surface. The force pushes the box a distance of $8\mathrm{.}0$ m $,$ in a time interval of $7\mathrm{.}0$ s $,$ and the speed changes from $v_1=0\mathrm{.}6\frac{m}{s}$ to

$($