• Support PF! Buy your school textbooks, materials and every day products Here!

Statics help

  • Thread starter tufftrav
  • Start date
3
0
Statics problem

i have been working on this problem now for 2 hours and haven't gotten anywhere,
taking the moment around joint a or b still leaves you with 2 unsolved equations. and suming the forces leaves with 2 also can anyone point me in the right direction, i jsut need to determine the reactions at a, and b i have drawn a Free body diagram. thanks

http://img255.imageshack.us/my.php?image=staticsum4.png"
 
Last edited by a moderator:

Answers and Replies

3
0
the length from a to b is 8' and 6' from b-e im sorry i didn't put that in my drawing
 
tiny-tim
Science Advisor
Homework Helper
25,789
249
Welcome to PF!

the length from a to b is 8' and 6' from b-e im sorry i didn't put that in my drawing
Hi tufftrav! Welcome to PF! :smile:

(This is the same question as in thread https://www.physicsforums.com/showthread.php?t=224637, isn't it?)

Can you please clarify:

Is the whole thing on a fixed pivot at the centre, E?

What is the force at C (also called E)?

Are A and B resting on the ground (you've called them "joints"), or what? :smile:
 
3
0
yea i double posted, the only pivot is at c, the is a force at e 100#, and force at d 100#, points a, and b were pin joints.
 
Last edited by a moderator:
PhanthomJay
Science Advisor
Homework Helper
Gold Member
7,119
463
I've always found these frame problems difficult. You have to use more than the equilibrium equationss when you have more unknowns than the number of those equations. The equilibrium equations will give you the y values of the reactions at a and b, but not the x values, which must exist at both these supports for stability. I think I would look at the recations due to each applied force separately, then combine them in the end to get the total reactions. When you look at them separately this way, you can identify which of the 2 members is a so called '2 force' member for that load, that is, it is not subject to shear, and has axial load only (internal bending moments in a member at pins cannot transfer at those pins to other members).
 

Related Threads for: Statics help

  • Last Post
Replies
9
Views
966
  • Last Post
Replies
2
Views
6K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
1
Views
6K
  • Last Post
Replies
1
Views
886
  • Last Post
Replies
3
Views
853
  • Last Post
Replies
13
Views
1K
Top