Compute Resultant Force Magnitude & Angle: Vector Addition

  • Thread starter aparra2
  • Start date
  • Tags
    Vector
In summary, the formula for computing resultant force magnitude and angle using vector addition is R = √(Fx^2 + Fy^2) and θ = tan^-1 (Fy/Fx). The direction of the resultant force can be determined by finding the angle using θ = tan^-1 (Fy/Fx). The purpose of computing the resultant force magnitude and angle is to determine the combined effect of multiple forces. Resultant force magnitude is always positive and to compute it using vector addition, individual forces must be broken down into their x and y components and then added together.
  • #1
aparra2
5
0
using the law of cosine , compuete the magnitude of the resultant force. Compute the angle of orienttion from the relationship tan thetha
2 F1=200g at 30 degrees, F2=200g at 120 degrees, F3=200g at 150 degrees. (the value should be close to 430 g of force at 103 degrees.
this is what i get but it dosent seem right 386.40 g at -14 degrees.
 
Physics news on Phys.org
  • #2
Well, how have you gone about solving the problem? Draw a diagram to start, then set up equations; post your work. We can't tell you if you're right if we can't see what you've done!
 
  • #3


I would approach this problem by first understanding the concept of vector addition and the law of cosines. Vector addition involves combining multiple vectors to determine the resultant force, which is the overall effect of all the individual forces acting on an object. The law of cosines is a mathematical formula that relates the lengths of the sides of a triangle to the cosine of one of its angles.

In this case, we have three forces (F1, F2, and F3) acting at different angles (30°, 120°, and 150°) with the same magnitude (200g). To determine the resultant force, we can use the law of cosines to find the magnitude and angle of the resultant force.

Using the law of cosines, we can calculate the magnitude of the resultant force as:

R^2 = F1^2 + F2^2 + 2F1F2cos(30°-120°) + 2F1F3cos(30°-150°) + 2F2F3cos(120°-150°)

R^2 = (200g)^2 + (200g)^2 + 2(200g)(200g)cos(-90°) + 2(200g)(200g)cos(-120°) + 2(200g)(200g)cos(-30°)

R^2 = 80000g^2 + 80000g^2 + 2(40000g^2)(-1) + 2(40000g^2)(-0.5) + 2(40000g^2)(0.866)

R^2 = 160000g^2 + 40000g^2 + 80000g^2 - 40000g^2 + 69280g^2

R^2 = 230280g^2

R = √230280g^2

R ≈ 480.06g

To find the angle of orientation, we can use the relationship tanθ = (F1sin30° + F2sin120° + F3sin150°) / (F1cos30° + F2cos120° + F3cos150°).

tanθ = (200g sin30° + 200g sin120° + 200g sin150°) / (200g cos30° +
 

1. What is the formula for computing resultant force magnitude and angle?

The formula for computing the resultant force magnitude and angle using vector addition is:
R = √(Fx^2 + Fy^2)
θ = tan^-1 (Fy/Fx)
where R is the magnitude of the resultant force, Fx and Fy are the x and y components of the individual forces, and θ is the angle between the resultant force and the x-axis.

2. How do you determine the direction of the resultant force?

The direction of the resultant force is determined by finding the angle between the resultant force and the x-axis using the formula θ = tan^-1 (Fy/Fx). This angle represents the direction in which the resultant force is acting.

3. What is the purpose of computing resultant force magnitude and angle?

The purpose of computing the resultant force magnitude and angle is to determine the combined effect of multiple forces acting on an object in a specific direction. This information is important in various fields of science, such as physics, engineering, and mechanics.

4. Can resultant force magnitude be negative?

No, resultant force magnitude cannot be negative. It is always a positive value, as it represents the combined effect of multiple forces acting on an object. If the individual forces are acting in opposite directions, the resultant force will have a smaller magnitude, but it will still be positive.

5. How do you use vector addition to compute resultant force magnitude and angle?

To use vector addition to compute resultant force magnitude and angle, you need to first break down each individual force into its x and y components. Then, add the x components together and the y components together separately. Finally, use the formula R = √(Fx^2 + Fy^2) to find the magnitude and θ = tan^-1 (Fy/Fx) to find the angle of the resultant force.

Similar threads

  • Introductory Physics Homework Help
Replies
2
Views
611
  • Introductory Physics Homework Help
Replies
26
Views
1K
  • Introductory Physics Homework Help
Replies
14
Views
309
  • Introductory Physics Homework Help
Replies
18
Views
788
  • Introductory Physics Homework Help
Replies
17
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
879
  • Introductory Physics Homework Help
Replies
7
Views
6K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
13
Views
2K
Back
Top