# Homework Help: Statics equilibrium truss

1. Mar 17, 2012

### JJRKnights

1. The problem statement, all variables and given/known data

Determine the largest mass m of the suspended block so that the force in any member does not exceed 52 kN(T) or 47 kN(C).

2. Relevant equations
ƩM = 0
ƩFy = 0
ƩFx=0

3. The attempt at a solution

Did I assume the arrows right?

Would this be the right track to solving this?
Solve for each piece.
Sum of moments, and solve for m?

2. Mar 17, 2012

### JJRKnights

Using Hibbeler as my book, no relevant examples in the book(as always), not enough explanation to solve the questions(as always). All the physics books I've ever encountered are so incomplete that I'm surprised they get published. If I never did physics, picked up one of these books and tried to learn it from the start, I'd probably get stuck in the first chapters because of the lack of explanation. My professor is even worse, let's give extremely easy examples, but when it comes to problems lets make them extremely hard.

3. Mar 17, 2012

### JJRKnights

All the back of the book says is:

Joint D: (F_DC)sin45 + (F_DE)cos30.25 - W = 0
Joint A: F_AG - 1.414Wsin45 = 0

Thanks for the detail Hibbeler.

4. Mar 17, 2012

### PeterO

If points E and C were attached/hinged to a wall, could you analyse CD and ED.
The scale of the diagram will show you how far apart E and C are - there is a 45o angle in there.

5. Mar 17, 2012

Solved it