$($d$)$ Now, take $m_1=7\mathrm{.}00kg,m_2=6\mathrm{.}00kg,$ and $m_2$ experiences a coefficient of friction with the flat surface that it rests upon, ${}_k=0\mathrm{.}400.$ Further, assume that the mass $m_2$ is initially sliding to the left. Write down three equations for the three unknowns of the problem $,T_1,$ and $T_2.$ The quantities $,T_1,$ and $T_2$ should be the only unknowns in your equations $($because you may remove the accelerations of the blocks $a_1$ and $a_2$ by using the rclations in part $($c$)).$

$m_{1}g-T_1=m_1{a}_1,T_2-{}_k{m}_{2}g=m_{2}a,T_2{r}_2-T_1{r}_1=Ia$

$($e$)$ Solve these equations to find $,T_1,$ and $T_2.$