Problem $2$

For the system bellow, estimate the moments created by forces $P$ and $F$ around on point $A,$ as well as the resultant moment:

In the Calder mobile $($see figure below$),$ the moments on each side of the point of suspension must be identical for balance to occur. Assume that $W=100lb,$ the weight of the lower arm is $F_E=150lb,a_1=4\mathrm{.}5ft,$ and $a_2=3ft.$ Calculate the magnitude of force $F_D$ and demonstrate that the arm is in balance about the point of suspension.