7.2 The truss system shown in Figure 7.2 is subjected to a lateral load of 20kN at Joint F and a 100kN vertical load at Joint J. Supports A and B consist of a pin and roller respectively: a) Draw a Free-Body Diagram of the truss and determine the reaction forces at supports A and B. (3 Marks) b) Determine the zero-force members. (1 Mark) c) Determine the forces present in members CF and HE through the Method of Sections. State if the member is in compression or tension. (3 Marks) 3m 20 kN D 3m Figure 7.2 3m H E D 4m 100 kN