Each member of the truss shown is made of steel (Est = 200GPa) and has the cross- sectional area shown. If the applied load P on point E is 40 kN,
a) determine the vertical deflection of joint C by using Castiglione's second theorem.
b) determine the horizontal deflection of joint C by using Castiglione's second theorem.
c) if a vertical force F is also applied at C to prevent its movement in vertical direction, determine the value of force F.