# Homework Help: Internal forces in truss

1. Jan 10, 2017

### fonseh

1. The problem statement, all variables and given/known data
For this problem , i found that the internal force AB at point A and point B pointed in the same direction ( as shown) in my working , so , how they cancel off each other ???Since they cant cancel off each other , so they are not stable , right ? The structure is statically indeterminate ?

2. Relevant equations

3. The attempt at a solution
It's in the 3rd photo

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• ###### 3.jpg
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2. Jan 10, 2017

### PhanthomJay

you forgot to consider the horizontal force reaction.

3. Jan 11, 2017

### fonseh

which
one ? which part ? Can you point out ?

4. Jan 11, 2017

### PhanthomJay

see your first attachment , bottom of page, sum of forces in x direction = 0.

5. Jan 11, 2017

### fonseh

One more question here , how to get the value of µ ? It's not stated in my textbook what is it ... And what is the usage of µ ?