A body of mass $m_1$ is connected with another body of mass $m_2$ with a massless string and pulled with force $F.$ Find the acceleration of the system and tension in the string.

Find the value of $T_1$ and $T_2$ in the given arrangement.

The mass of an elevator is $800 \mathrm{kg}.$ Calculate the magnitude of tension produced in the cable of the elevator when

$\left(\mathrm{i}\right)$ It is stationary.

$\left(\mathrm{ii}\right)$ It is ascending with an acceleration of $4 \mathrm{m}{ \mathrm{s}}^{-2}.$

$\left(\mathrm{iii}\right)$ It is descending with same acceleration. (Take $g=10 \mathrm{m}{ \mathrm{s}}^{-2})$

$\left(\mathrm{i}\right)$ What are impulsive forces? Give two examples.

$\left(\mathrm{ii}\right)$ How can we measure impulse from force-time graph?

$\left(\mathrm{iii}\right)$ Write $SI$ unit of impulse.