A horizontal plank $4\mathrm{.}00$m long and having mass $20\mathrm{.}0$kg rests on two supports,$$one at the far left end,$$and a second $1\mathrm{.}00$m from the right end.$$Find the magnitude of the force exerted on the plank by the second pivot.$$

$($Hint:$$If you use the far left end as the point from which you will calculate the torques about it will simplify the problem.$)$

Remember equilibrium conditions mean that sum of torques and forces equals zero.