Vector Addition Help: Finding the Resultant Vector using the Component Method

[VectorHugo]

EDIT: ****Nevermind, I just mis-typed everything into my calculator. I had to put my X and Y values in parenthesis - ie sqrt((29.47)^2 + (-5.32)^2)**************

I *think* I am doing this right, but I can never get the right answer. Does anybody notice what is going wrong?

The correct answer to this problem is an angle of 10.2 degrees and a magnitude of 30.2 m.

Homework Statement

A football player runs the pattern given in the drawing by the three displacement vectors A, B, and C. The magnitudes of these vectors are A = 5.00 m, B = 15 m, and C = 18 m. Using the component method, find the magnitude and direction (theta) of the resultant vector A + B + C.

http://univirtual.info/elementaryphysics/art/images/cutnell3158c01/image_n/ngr021.gif

Homework Equations

Dx: Ax + Bx + Cx
Dy: Ay + By + Cy

The Attempt at a Solution

Ax: (5 cos 90) = 0 m
Bx: (15 cos 0) = 15 m
Cx: (18 cos 325) = 14.74 m

Ay: (5 sin 90) = 5 m
By: (15 sin 0) = 0 m
Cy: (18 sin 325) = -10.32 m *i measured all the angles from the x axis*

Dx = 29.74 m
Dy = -5.32 m

D = sqrt(29.74² + -5.32²) = 29.26 m

theta = tan^-1 (Dy/Dx) = 10.1 degrees

 

[AvroArrow]

I have no idea why this isn't working. I just can't seem to get the right answer. Any help would be appreciated.Thanks!

 

[tomcue]

I would first check to ensure that the values for the displacement vectors A, B, and C were correctly entered into the component method equations. I would also double check the trigonometric calculations for each component to make sure they were accurate. Additionally, I would verify that the angles were measured correctly from the x-axis, as this could impact the final result.

If all of these factors were correct, I would suggest using a different method to solve for the resultant vector, such as the graphical method or the parallelogram method, to see if the results match. This would help to confirm if there is an error in the calculations or if there is an issue with the given values.

I would also recommend reviewing the steps and equations used in the component method to ensure they were applied correctly. Sometimes, a small error in calculation or a missed step can lead to an incorrect result.

Overall, it is important to carefully review and double check all calculations and methods used in order to accurately determine the resultant vector. If the issue persists, it may be helpful to seek guidance from a teacher or peer to identify any potential errors.