Problems

$3\mathrm{.}1$ A $30-lb$ force is applied to the control rodAB as shown. Knowing that

the length of the rod is $8$ in $.$ and that $=30,$ determine the moment of the force

about $B$ by resolving the force $(a)$ into horizontal and vertical components, $(b)$ into

components along $AB$ and in a direction perpendicular to $AB.$

$3\mathrm{.}2$ A $30-lb$ force is applied to the control rodAB as shown. Knowing that

the length of the rod is $8$ in $.$ and that the moment of the force about $B$ is $180ib*in.$

clockwise, determine the value of $.$

Fig. P$3\mathrm{.}3$ and P$3\mathrm{.}4$

$3\mathrm{.}3$ For the brake pedal shown, determine the magnitude and direetion of

the smallest force $P$ which has a $130-N*m$ clockwise moment about $B.$

$.3\mathrm{.}4$ A force $P$ is applied to the brake pedal at $A.$ Knowing that $P=450N$

and $=30,$ determine the moment of $P$ abo$$t $B.$

$3\mathrm{.}5$ A $300-N$ force $P$ is applied at point $A$ of the bell crank shown.

$($a$)$ Compute the moment of the force $P$ about $O$ by resolving it into horizontal and

vertical components. $($b$)$ Using the result of part $a,$ determine the perpendicular

distance from $O$ to the line of action of $P.$

$3\mathrm{.}6$ A $400-N$ force $P$ is applied at point $A$ of the bell crank shown.

$($a$)$ Compute the moment of the force $P$ about $O$ by resolving it into components

along line $OA$ and in a direction perpendicular to that line. $($b$)$ Determine the

magnitude and direction of the smallest force $Q$ applied at $B$ which has the same

moment as $P$ about $O.$

Do $3\mathrm{.}1-3\mathrm{.}6$