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

Vector addition of forces

  • Thread starter Suy
  • Start date

Suy

102
0
1. Homework Statement
Three cables pull on the pipe such that they create a resultant force having magnitude FR. If two
of the cables are subjected to known forces, as shown in the figure, determine the direction θ of
the third cable so that the magnitude of force F in this cable is a minimum. All forces lie in the
x–y plane.What is the magnitude of F? Hint: First find the resultant of the two known forces.
Prob._2-31.jpg

2. Homework Equations



3. The Attempt at a Solution
I have the solution
but i don't understand "minimum" in this question?
"the third cable so that the magnitude of force F in this cable is a minimum. "
 

JJBladester

Gold Member
286
2
...determine the direction θ of the third cable so that the magnitude of force F in this cable is a minimum.
[tex]F_{R}=\left[1200sin45\textdegree+800cos30\textdegree\right]\hat{i}+\left[1200cos45\textdegree-800sin30\textdegree\right]\hat{j}[/tex]

[tex]F_{R}=1541.35\hat{i}+448.53\hat{j}[/tex]

[tex]\left|F_{R}\right|=1605.28[/tex]

[tex]tan^{-1}\left (\frac{448.53}{1541.35}\right)=16.22\textdegree[/tex]

Cheers!
 
1
0
wat is the solution...can u give me?
 

Related Threads for: Vector addition of forces

  • Posted
Replies
2
Views
1K
  • Posted
Replies
6
Views
4K
Replies
1
Views
1K
Replies
4
Views
4K
Replies
2
Views
175
  • Posted
Replies
3
Views
2K
Replies
4
Views
5K
Replies
9
Views
16K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top