Equivalent force and couple moment

In summary, the student is struggling with finding moments and couples in a physics problem. They have found the magnitude and angle of the resultant force, but are unsure of how to proceed. They are using the equation $$\vec M = \vec r \times \vec F$$ to find ##\vec r##, but are having trouble with the cross product. They have found the answer and no longer need assistance.
  • #1
marsupial
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Homework Statement


I will post a photo of the question in the thread once I've created it. I have found the magnitude and angle of the resultant force, but I am unsure of how to proceed. I find moments and couples confusing.

Homework Equations



$$\vec M = \vec r \times \vec F$$

The Attempt at a Solution



So, to find ##\vec r## I chose a point on ##\vec F## (1, 0.8069) (call it C), and calculated ##r_{BC}##: ##r_{c} = -7i + 0.8069j##. Then I took the cross product of r and F, and got 41.58kN.m, but this is incorrect, and I am stumped.
 
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  • #2
1.jpeg
 
  • #3
i found the answer, thanks.
 

FAQ: Equivalent force and couple moment

What is an equivalent force?

An equivalent force is a single force that has the same effect on an object as a system of multiple forces acting on the same object. It is a simplified representation of the original forces and can help make calculations easier.

How is equivalent force calculated?

Equivalent force is calculated by finding the resultant force of the original forces. This can be done using vector addition or by using the parallelogram method. The magnitude and direction of the resultant force will be the equivalent force.

What is a couple moment?

A couple moment is a pair of forces that are equal in magnitude, opposite in direction, and parallel to each other. They do not have a net force or a net torque on an object, but they create a rotational effect on the object.

How is couple moment different from a single force?

A single force has a magnitude and a direction, while a couple moment has two forces with equal magnitude and opposite directions. A single force can cause translational motion, while a couple moment only causes rotational motion.

How can equivalent force and couple moment be used in real-world applications?

Equivalent force and couple moment are commonly used in structural engineering to analyze and design buildings, bridges, and other structures. They can also be used in mechanical engineering to design machines and mechanisms that can withstand different forces and moments. Additionally, these concepts are important in physics and other branches of science that deal with forces and motion.

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