The force method equation is based on the displacement compatibility condition. Then, can the result obtained by the force method satisfy the equilibrium

The force method equation is based on the displacement compatibility condition. Then, can the result obtained by the force method satisfy the equilibrium

The concept of attention method: take the force as the basic unknown quantity, and analyze on the basis of automatically meeting the balance conditions. At this time, we should mainly solve the deformation coordination problem. This kind of analysis method is called force method

Are the projections of forces on two parallel axes in the same direction necessarily equal? Are the projections of two parallel and equal forces on the same axis necessarily equal?
The subject of theoretical mechanics

The projections of forces on two parallel axes in the same direction must be equal!
The projections of two parallel and equal forces on the same axis are not necessarily equal

Decompose the 180n vertical downward force into two forces, one component is equal to 240n in the horizontal direction, and find the size and direction of the other component
In a hurry

Another force:
The size is under the root sign (180 square + 240 square), that is 300N
The direction is inclined downward to the right, and the included angle with the horizontal direction is about 37 degrees (tangent = 3 / 4)