# Solving Statics Problems with Couples - Help Needed

• btbam91
In summary, a couple in statics is a pair of equal and opposite forces that act on a body, resulting in a rotational force around a pivot point. The magnitude of a couple can be calculated by multiplying one of the forces by the distance between them. The principle of moments states that for an object to be in equilibrium, the sum of the moments must be zero. To solve statics problems involving couples, one can set up equations using the principle of moments and carefully label all known and unknown quantities. Common mistakes when solving these problems include forgetting to account for the direction of the moment, not considering all forces, and using incorrect units. It is important to double check the final answer to ensure it makes sense in the given context.
btbam91
Hey guys, I'm kind of struggling with a piece of this problem.

[PLAIN]http://img97.imageshack.us/img97/6862/372h.png

This isn't my problem exactly (different numbers and units) but I am having trouble completing part c. I successfully did parts a and b by putting the two forces down, finding the distance between the two forces, and using M = Fd to find F.

But I'm not sure how to do c since there's no way of knowing d.

Thanks!

Last edited by a moderator:
Figured this one out! It's the longest distance possible (A to C)

## What is a couple in statics?

A couple is a pair of equal and opposite forces acting on a body but not along the same line. This results in a rotational force or moment around a point, known as the pivot point or fulcrum.

## How do you calculate the magnitude of a couple?

The magnitude of a couple can be calculated by multiplying one of the forces by the distance between the forces. This distance is known as the moment arm or lever arm.

## What is the principle of moments?

The principle of moments states that for an object to be in equilibrium, the sum of the moments (or torques) acting on the object must be zero. This means that the clockwise moments must be equal to the counterclockwise moments.

## How do you solve statics problems involving couples?

To solve statics problems involving couples, you can use the principle of moments and set up equations to find the unknown forces or distances. It is important to draw a clear diagram and label all the known and unknown quantities.

## What are some common mistakes when solving statics problems with couples?

Some common mistakes when solving statics problems with couples include forgetting to account for the direction of the moment (clockwise or counterclockwise), not considering all the forces acting on the object, and not using the correct units for distance and force. It is also important to check your final answer to ensure it makes sense in the context of the problem.

• Engineering and Comp Sci Homework Help
Replies
5
Views
949
• Engineering and Comp Sci Homework Help
Replies
2
Views
1K
• Engineering and Comp Sci Homework Help
Replies
6
Views
1K
• Engineering and Comp Sci Homework Help
Replies
1
Views
8K
• Engineering and Comp Sci Homework Help
Replies
6
Views
2K
• Engineering and Comp Sci Homework Help
Replies
1
Views
704
• Introductory Physics Homework Help
Replies
6
Views
963
• Engineering and Comp Sci Homework Help
Replies
1
Views
2K
• Engineering and Comp Sci Homework Help
Replies
25
Views
5K
• General Math
Replies
1
Views
786