# Finding the Magnitude of 3 Forces on a Square

• alijan kk
In summary: We need to see a diagram of the vectors, where they start, and...In summary, the correct answer is "nearest to 2".

## Homework Statement

Three forces each of magnitude 1N act from one corner towards the other corner of a square there sum has a magnitude nearest to :

## The Attempt at a Solution

diagonal of a square is equal to √2 , the answer should be 3√2

alijan kk said:

## Homework Statement

Three forces each of magnitude 1N act from one corner towards the other corner of a square there sum has a magnitude nearest to :

## The Attempt at a Solution

diagonal of a square is equal to √2 , the answer should be 3√2
Let's see what your diagram looks like. Do you know how to resolve vectors into components so that the vectors can be summed vectorially?

Chestermiller said:
Let's see what your diagram looks like. Do you know how to resolve vectors into components so that the vectors can be summed vectorially?
yes I know vector resolution, but I want a hint on how to picturize this question

alijan kk said:
yes I know vector resolution, but I want a hint on how to picturize this question
Try laying the square out so that the corner at which the forces are applied is the lower left corner, and this corner coincides with the origin of an x-y Cartesian coordinate system. What are the components of the three forces in the x direction and in the y direction?

alijan kk
Chestermiller said:
Try laying the square out so that the corner at which the forces are applied is the lower left corner, and this corner coincides with the origin of an x-y Cartesian coordinate system. What are the components of the three forces in the x direction and in the y direction?
the net force(x) is in the -x direction 3/√2 and the Fnet(y) is also 3/√2 in -y direction

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alijan kk said:
the net force(x) is in the -x direction 3/√2 and the Fnet(y) is also 3/√2 in -y direction
The question sounds like it is multiple choise, where you have not shown the choises. The correct answer might be very simple. Otherwise, you may still need to make a diagram and show details of your work. Which corner is "the other corner"? Are all the forces pointing in the same direction?

PS. Why do you think that the lay-out of the square effects the total magnitude of the force?

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FactChecker said:
The question sounds like it is multiple choise, where you have not shown the choises. The correct answer might be very simple. Otherwise, you may still need to make a diagram and show details of your work. Which corner is "the other corner"? Are all the forces pointing in the same direction?

PS. Why do you think that the lay-out of the square effects the total magnitude of the force?
you are right its a multiple choice questions
the options are
a: nearest to 3
b:nearest to 2
c: nearest to 1
d: nearest to 2.4

alijan kk said:
the net force(x) is in the -x direction 3/√2 and the Fnet(y) is also 3/√2 in -y direction
That's not what I get.

alijan kk said:
diagonal of a square is equal to √2 , the answer should be 3√2
First, the diagonal of a unit square is √2 in length, but that isn't relevant in this problem. If you draw the diagram as @Chestermiller suggested, all forces extend out from the lower left corner of the square. All three forces have a magnitude of 1, so the force toward the upper right corner of the square doesn't reach that corner point.
Second, you apparently have multiplied √2 by 3 to get your answer, but that is incorrect for two reasons -- the magnitude of each force is 1, not √2, and the resultant of a force is not simply the sum of the magnitudes.

alijan kk said:
the net force(x) is in the -x direction 3/√2 and the Fnet(y) is also 3/√2 in -y direction
No.
Chestermiller said:
That's not what I get.
Nor do I.

Chestermiller
To expand on what Chestermiller said in post #4, draw your diagram with the lower left corner of the square at the origin, and with the three vectors extending from the origin toward the three other corners of the square. Label the endpoints of all three vectors. Note that the diagonal vector doesn't reach the corner opposite the origin. Add the three vectors using vector addition. The magnitude of the resultant vector is what you want to find.

Mark44 said:
To expand on what Chestermiller said in post #4, draw your diagram with the lower left corner of the square at the origin, and with the three vectors extending from the origin toward the three other corners of the square.
That is the situation that I first assumed. But the statement given is "from one corner towards the other corner of a square". If they all point in the same direction, the answer is simple and quite different.
We need to see a diagram of the vectors, where they start, and where they end. Or tell us that they all start at the same corner and point toward different corners.

What is the component of the diagonal force in the x direction? in the y direction?

FactChecker said:
But the statement given is "from one corner towards the other corner of a square". If they all point in the same direction, the answer is simple and quite different.
Yes. However, since a square has four corners, "other corner of a square" is unclear. Do the vectors all start from one point, and point to the opposite corner of the square?

FactChecker said:
We need to see a diagram of the vectors, where they start, and where they end. Or tell us that they all start at the same corner and point toward different corners.
Or at least a clear description of the problem.

Mark44 said:
First, the diagonal of a unit square is √2 in length, but that isn't relevant in this problem. If you draw the diagram as @Chestermiller suggested, all forces extend out from the lower left corner of the square. All three forces have a magnitude of 1, so the force toward the upper right corner of the square doesn't reach that corner point.
Second, you apparently have multiplied √2 by 3 to get your answer, but that is incorrect for two reasons -- the magnitude of each force is 1, not √2, and the resultant of a force is not simply the sum of the magnitudes.No.
Nor do I.
you are right i made that mistake, but why it is not simply the sum of vector magnitudes, 3 ?

alijan kk said:
you are right i made that mistake, but why it is not simply the sum of vector magnitudes, 3 ?
Have they not taught you this in your course?

Chestermiller said:
Have they not taught you this in your course?
i am just confused that why the corner to corner is diagonal why not the nearest corner could be the corner, and if the force is like you said from left down corner and extends to right upward corner ,then why can't we just add three vectors and get the magnitude of 3.

alijan kk said:
you are right i made that mistake
We still don't have a clear description of the problem. Do the vectors all point in the same direction, or does each one point to a different corner of the square?

We can't give useful help if we don't know what the problem is.

Mark44 said:
We still don't have a clear description of the problem. Do the vectors all point in the same direction, or does each one point to a different corner of the square?

We can't give useful help if we don't know what the problem is.
actually i also wanted to know if the problem is correct or wrong, it is created by over physics proffesor

What have you learned in your course about how to add vectors having different magnitudes and directions to obtain their resultant?

alijan kk said:
actually i also wanted to know if the problem is correct or wrong, it is created by over physics proffesor
It depends on what the problem is.
From the original post:
alijan kk said:
Three forces each of magnitude 1N act from one corner towards the other corner of a square
As I already mentioned, the square has three other corners. Are the vectors pointing to different corners or are they all pointing toward the opposite corner?

Chestermiller said:
What have you learned in your course about how to add vectors having different magnitudes and directions to obtain their resultant?
yes, we have learned vector addition by head to tail rule and by law of cosines.

Mark44 said:
It depends on what the problem is.
From the original post:
As I already mentioned, the square has three other corners. Are the vectors pointing to different corners or are they all pointing toward the opposite corner?

This is the only description given and the answer is nearest to 2.4

alijan kk said:
yes, we have learned vector addition by head to tail rule and by law of cosines.

That answer 2.4 is only correct for the problem where all the vectors start at the same corner and each vector points to a different corner. Given that problem, can you get that answer?

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alijan kk said:
you are right i made that mistake, but why it is not simply the sum of vector magnitudes, 3 ?
3 is only correct if they all point in the same direction. any "zig-zagging" reduces the magnitude of the sum.

jbriggs444

## What is the purpose of finding the magnitude of 3 forces on a square?

The purpose of finding the magnitude of 3 forces on a square is to understand the overall effect of these forces on the square. It allows us to determine the net force acting on the square, as well as the direction of this net force.

## What type of forces are typically considered when finding the magnitude of 3 forces on a square?

Typically, we consider external forces acting on the square, such as gravity and applied forces. Internal forces, such as tension within the square, are usually not considered as they cancel out in the calculation of net force.

## What is the formula for finding the magnitude of 3 forces on a square?

The formula for finding the magnitude of 3 forces on a square is: Fnet = √(Fx² + Fy²), where Fx and Fy are the horizontal and vertical component of the net force, respectively.

## How do you determine the direction of the net force when finding the magnitude of 3 forces on a square?

To determine the direction of the net force, we use the trigonometric concept of finding the angle of a right triangle. We can use the inverse tangent function (tan⁻¹) to find the angle, which represents the direction of the net force.

## What are the units of measurement for the magnitude of 3 forces on a square?

The units of measurement for the magnitude of 3 forces on a square are typically in Newtons (N) or pounds (lbs), depending on the unit system being used. It is important to ensure that all forces are in the same unit before calculating the magnitude.