Question

The 12.2-m crane weighs 18 kn and is lifting a 67-kn load. the hoisting cable (tension t1) passes over a pulley at the top of the crane and attaches to an electric winch in the cab. the pendant cable (tension t2), which supports the crane, is fixed to the top of the crane. find the tensions in the two cables and the force fp at the pivot.

Answer 1

I can't seem to figure out the angle between T1 and T2. So suppose, it is 10º; then T2 makes an angle of 35º w/r/t horizontal, and T1 makes an angle of 45º. 
Sum the moments about the base of the crane; Σ M = 0. 0 = T2*cos35*L*cos40 + T1*cos45*L*cos40 - T2*sin35*L*sin40 - T1*sin45*L*sin40 - W*(L/2)*sin40 - T1*L*sin40 → length L cancels where W = 18 kN 
0 = 0.259*T2 - 43kN T2 = 166 kN