The hook and spring assembly shown in the figure are in equilibrium: F1 A K 40 F 2 B 7 x 30 F 3 COLLAPSE IMAGES F1 = 160 lb F2 = 160 lb F3 = 60 lb k = 1000 lb/ftCalculate the magnitude of the resultant force. lb ENTER 3 tries remaining. 1 point(s) possible Calculate the orientation of the spring measured counterclockwise from the positive x axis. 3 deg ENTER 3 tries remaining. 1 point(s) possible Calculate the change in length of the spring due to the applied forces. in ENTER 3 tries remaining. 1 point(s) possible A new force F4 is added. To make the spring extend horizontally (in the direction of x) and stay in equilibrium, calculate the magnitude of F4. F 1 K A 40 F 2 30 F 3 130 0 F 4 lb ENTER 3 tries remaining. 1 point(s) possible In the situation above, what is the change in length of the spring due to the four applied forces? in ENTER 3 tries remaining. 1 point(s) possible