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

Tension/Resultant Forces

  • Thread starter Auburn2017
  • Start date
  • #1
59
1

Homework Statement


The problem is shown in the image attached.

Homework Equations


∑F = -235i -Fi +Tcos25i + Tsin25j +210cos25i +210sin25j
Moment = r x F[/B]

The Attempt at a Solution


I have tried various things. I tried summing all the moments and then setting that equal to zero to find T. I have tried just adding the forces and setting equal to zero to find T. None of these approaches have helped so far. Right now I am just interested at find T. Could someone just point me in the right direction to start. Thanks much.
 

Attachments

Answers and Replies

  • #2
billy_joule
Science Advisor
1,200
330
I have tried various things. I tried summing all the moments and then setting that equal to zero to find T.
That approach will find T. Show your work and we'll see what went wrong.
 
  • #3
149
11
Chose the positive for finding moment. You must use ΣM=0.
Note M=||rxF||=r.F.sina
 
  • #4
59
1
That approach will find T. Show your work and we'll see what went wrong.
This is what I get. I also know if the distance between the force and the point is perpendicular then the moment just equals rF. If you do this then you can get the right answer but I do not understand the sign on the four terms...
 

Attachments

Last edited:
  • #5
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
32,724
5,031
This is what I get. I also know if the distance between the force and the point is perpendicular then the moment just equals rF. If you do this then you can get the right answer but I do not understand the sign on the four terms...
Let's just consider the moment due to T to begin with. The moment is the force times the perpendicular distance between the axis and the line of action of the force, right? What is that perpendicular distance?
 
  • #6
59
1
Let's just consider the moment due to T to begin with. The moment is the force times the perpendicular distance between the axis and the line of action of the force, right? What is that perpendicular distance?
Easy.. 0.1m
 
  • #7
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
32,724
5,031

Related Threads on Tension/Resultant Forces

Replies
15
Views
2K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
2
Views
841
  • Last Post
Replies
12
Views
2K
  • Last Post
Replies
15
Views
626
  • Last Post
Replies
9
Views
3K
  • Last Post
Replies
1
Views
444
  • Last Post
Replies
3
Views
1K
Top