Solution of task 1.1.10 from the collection of Kepe OE

Solution of task 1.1.10 from the collection of Kepe OE

1.1.10
A plane system of convergent forces acts on a solid at the point O: F1 = 1H, F2 = 2H,
F3 = 3H, F4 = 4H. Determine the sum of the projections of the given forces on the Oy axis if the angles? = 30 ° are given,
? = 45о,? = 60о.(Otvet -3.22)