Q$\mathrm{.}3)$ A winch $($pulley with applied torque$)$ at $D$ is used to raise the load $W=2800lb$ by applying

a constant torque, $M_D.$ A horizontal force of $1200$ lb acts at joint $G$ and a vertical load of $500$ lb

acts at joint $E.$ The structure is supported by a

roller support at $H$ and a pin support at I. The

radii of winch $D$ and pulley A are each $2$ feet.

Assume friction is negligible between the cable

and the pulley. Assume all members of the

structure have negligible mass. Assume points

$A,E,$ and $F$ are collinear.

a$)$ Determine the torque $M_D$ required to

raise the load at a constant velocity.

b$)$ Determine the forces in members $FH,$

$FG,EF$ and $DG.$ State whether each

member is in tension or compression.