Question $1$: $10$ points.

The cantilevered frame structure carries vertical loads P kN at notes $D,F,H$ and I $.$ Use the method of sections to determine the forces in members $a,b$ and c $,$ as a function of the problem parameters L and P $.$

Figure $1$: Cantilevered trame structure.

State if the members are in tension or compression.

Question $2$: $10$ points.

If the maximum tensile force that any member in Figure $1$ can carry is $15$ kN $,$ and the maximum compressive force is $10$ kN $($before buckling$),$ what is the maximum value of loads P that can be carried.