(Solved): Problem 2 Determine the maximum force P which can be applied to the roof truss as shown if the maxim ...

Problem 2 Determine the maximum force P which can be applied to the roof truss as shown if the maximum tensile force the members can support is 115.78 and the maximum compressive force the members can support is 57.89 kip. What is the critical member? The answer is P = 15 kip; Member BC is critical, but I need help with the step by step process for questions like these.