The $0\mathrm{.}611\mathrm{.}00-$m lid ABCD of a storage bin is hinged along side AB and is held open by

looping cord DEC over a frictionless hook at E$.$ If the tension in the cord is $66$ N$,$ determine the moment

about each of the coordinate axes of the force exerted by the cord at D$.$

Ans:Mx $=31\mathrm{.}2$N m$,$ My $=13\mathrm{.}20$N m$,$ Mz $=2\mathrm{.}42$N m

Problem $4.$ To lift a heavy crate, a man uses a block and tackle attached to the bottom of an I$-$beam at

hook B $.$ Knowing that the moments about the y and the z axes of the force exerted at B by portion AB

of the rope are, respectively, $120$N m and $460$N m$,$ determine the distance a$.$

Ans:a $=1\mathrm{.}252$m