Three forces acting on object, find net force

In summary, to find the magnitude of the net force acting on an object, we need to use vector addition by adding the individual forces together. We can find the components of each force using trigonometry and then use the Pythagorean theorem to find the magnitude of the net force. In this case, the magnitude of the net force is 11.4 N.
  • #1
Naeem
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Forces

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Three forces F1, F2 and F3 act on an object as shown in the free-body diagram above. F1 has a magnitude of 6 N while F2 and F3 each have a magnitude of 3 N. All forces make angles of 30° with the x-axis as shown.

What is the magnitude of Fnet, the net force acting on the object?

|Fnet| = N


I know, this problem isn't too hard, we need to add vectors considering the angles ( both in x -y directions )

I just forgot how to do this, can anybody help.
 
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  • #2


Hello there! I am happy to help you with this problem.

To find the magnitude of the net force, we need to use vector addition. This means we need to add the individual forces together to get the total force acting on the object.

First, we need to find the components of each force in the x and y directions. We can do this by using trigonometry. For F1, the x-component would be 6cos30° and the y-component would be 6sin30°. Similarly, for F2 and F3, the x-components would be 3cos30° and the y-components would be 3sin30°.

Next, we can add these components together to get the total x and y components of the net force. This would be:

Fnet,x = 6cos30° + 3cos30° + 3cos30° = 9.9 N
Fnet,y = 6sin30° + 3sin30° + 3sin30° = 5.2 N

Now, we can use the Pythagorean theorem to find the magnitude of the net force:

|Fnet| = √(Fnet,x² + Fnet,y²) = √(9.9² + 5.2²) = 11.4 N

So, the magnitude of the net force acting on the object is 11.4 N. I hope this helps! Let me know if you have any further questions.
 
  • #3


To find the net force acting on the object, we need to use vector addition. This means adding the individual forces together to find the resultant force. In this case, we can use the Pythagorean theorem and trigonometric functions to find the magnitude and direction of the net force.

First, we need to break down each force into its x and y components. We can do this by using the given angle and the trigonometric functions.

For F1:
Fx1 = F1 cos 30° = 6 cos 30° = 5.2 N
Fy1 = F1 sin 30° = 6 sin 30° = 3 N

For F2:
Fx2 = F2 cos 30° = 3 cos 30° = 2.6 N
Fy2 = F2 sin 30° = 3 sin 30° = 1.5 N

For F3:
Fx3 = F3 cos 30° = 3 cos 30° = 2.6 N
Fy3 = F3 sin 30° = 3 sin 30° = 1.5 N

Now, we can add the x and y components separately to find the net force:

Fnet,x = Fx1 + Fx2 + Fx3 = 5.2 N + 2.6 N + 2.6 N = 10.4 N
Fnet,y = Fy1 + Fy2 + Fy3 = 3 N + 1.5 N + 1.5 N = 6 N

Using the Pythagorean theorem, we can find the magnitude of the net force:

|Fnet| = √(Fnet,x² + Fnet,y²) = √(10.4² + 6²) = 12.2 N

Therefore, the magnitude of the net force acting on the object is 12.2 N. To find the direction, we can use the inverse tangent function:

θ = tan^-1 (Fnet,y/Fnet,x) = tan^-1 (6/10.4) = 31.8°

Thus, the net force has a magnitude of 12.2 N and is directed at an angle of 31.8° from the x-axis.
 

FAQ: Three forces acting on object, find net force

1. What is the formula for calculating net force when three forces are acting on an object?

The formula for calculating net force is Fnet = F1 + F2 + F3, where F1, F2, and F3 are the individual forces acting on the object.

2. How do you find the direction of the net force when three forces are acting on an object?

To find the direction of the net force, you must add the individual forces vectorially. This means that you must take into account both the magnitude and direction of each force. The final result will give you the direction of the net force.

3. Can the net force on an object be zero if three forces are acting on it?

Yes, it is possible for the net force on an object to be zero if three forces are acting on it. This is because if the three forces are equal in magnitude and opposite in direction, they will cancel each other out and result in a net force of zero.

4. What is the difference between net force and individual force?

Net force is the overall force acting on an object, which is the sum of all the individual forces acting on it. Individual force refers to each individual force acting on the object.

5. How can you determine the magnitude of the net force when three forces are acting on an object?

To determine the magnitude of the net force, you must use the Pythagorean theorem. This means squaring each individual force, adding them together, and then taking the square root of the result. The answer will give you the magnitude of the net force.

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