Statics: parallel forces problem

In summary, the conversation was about determining the x- and y-coordinates of a point that the resultant of parallel forces passes through. The individual described their attempt at a solution, which involved finding the resultant forces and the moment of each axis. They then used the formula r x R = M to solve for x and y, but initially got the wrong answer because they switched the variables. However, after correcting their mistake, they were able to get the correct solution.
  • #1
c1tonsoup
2
0

Homework Statement



Determine the x- and y-coordinates of a point through which the resultant of the parallel forces passes.

The Attempt at a Solution


The first thing I did was to find the resultant forces, which is R = 0i + 0j -125 k
Then I found the moment of each axis
so
M = (-65(12) -65(6) +60(12) +35(12) ) i + (-65(11)-35(15)+90(15))j + 0k
M = -30 i + 110 j

Then the next thing I did is
r x R = M
so
(xi + yj + zk) x (-125 k) = (-30 i +110 j)
-125y i + 125x j = -30 i + 110 j
so x and y I got is
x= 0.24
y = 0.88

why is it wrong?
Thanks for the help
 

Attachments

  • Capture.JPG
    Capture.JPG
    24.9 KB · Views: 1,361
Physics news on Phys.org
  • #2
Did you switch x and y ?
 
  • #3
BvU said:
Did you switch x and y ?
Haha I just did and got the right answer. But i don't understand why that's the case. i did all my math right
 
  • #4
c1tonsoup said:
-125y i + 125x j = -30 i + 110 j
Says y = 30/125 and x = 110/125 !
 

Related to Statics: parallel forces problem

1. What is statics?

Statics is a branch of mechanics that deals with the study of forces acting on objects at rest or in a state of constant motion.

2. What are parallel forces?

Parallel forces are forces that act on an object in the same direction, but have different points of application.

3. What is a parallel forces problem?

A parallel forces problem is a type of statics problem where two or more parallel forces act on an object and the goal is to determine the resultant force and its direction.

4. How do I solve a parallel forces problem?

To solve a parallel forces problem, you can use the principle of moments which states that the sum of clockwise moments is equal to the sum of counterclockwise moments. You can also use trigonometry and vector addition to determine the resultant force and its direction.

5. Why is it important to understand parallel forces in statics?

Understanding parallel forces is important in statics because it allows us to analyze and predict the behavior of objects under different forces. This is crucial in fields such as engineering and architecture where the stability and safety of structures depend on the proper understanding and application of parallel forces.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
7
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
5
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
14
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
11
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
5
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
11
Views
302
Replies
7
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
8
Views
269
Back
Top