Vector A points in the negative x direction. Vector B points at an angle of 27.0 degress above the positive x axis. Vector C has a magnitude of 20 m/s and points in a direction 39.0 degress below the positive x axis.

Given that A+B+C=0, find the magnitudes of A and B.

A = a*(-1, 0)^T

B = b*(cos(27°), sin(27°))^T
C = 27*(cos(39°), -sin(29°))^T

By using the identity imposed on us by the task, we immediately obtain the result by solving the emerging L.E.S..

To solve this problem, we will use vector addition and combination of components.

Step 1: Representing the given vectors in terms of their components
Let's define the x-axis as pointing in the positive direction, and the y-axis as pointing perpendicular to the x-axis.

Vector A points in the negative x-direction. Therefore, its x-component will be negative and its y-component will be zero.
Let's denote the magnitude of vector A as A, and its x-component as Ax and y-component as Ay.

Vector B points at an angle of 27.0 degrees above the positive x-axis. To find its components, we can use trigonometry.
The magnitude of vector B will be denoted as B, and its x-component as Bx and y-component as By.

Vector C has a magnitude of 20 m/s and points in a direction 39.0 degrees below the positive x-axis.
To find its components, we can also use trigonometry. The magnitude of vector C will be denoted as C, and its x-component as Cx and y-component as Cy.

Now, let's analyze the given equation A + B + C = 0:
(Ax + Bx + Cx)i + (Ay + By + Cy)j = 0i + 0j

Since the equation components on both sides must be equal, we can write two separate equations:
Ax + Bx + Cx = 0 (i-component equation)
Ay + By + Cy = 0 (j-component equation)

Step 2: Solving for the components of vector A and B
From the i-component equation, we can conclude that Ax + Bx + Cx = 0.
Since Ax is negative (as it points in the negative x-direction), we can rewrite the equation as |Ax| - |Bx| - |Cx| = 0.

From the j-component equation, we can conclude that Ay + By + Cy = 0.

Step 3: Finding the magnitudes of vector A and B
We know that vector A points solely in the x-direction, so its y-component (Ay) is 0. Thus, the magnitude of vector A is simply |Ax|.

For vector B, we need to use the Pythagorean theorem to determine its magnitude. The magnitude of vector B (B) can be calculated as B = sqrt(Bx^2 + By^2).

Therefore, to find the magnitudes of vector A and B, we need to determine |Ax| and B.

Step 4: Substituting the given information
Unfortunately, the problem statement does not provide numerical values for the components of vector B or C. Therefore, we can't determine the magnitudes of vector A and B without specific values.

To find the magnitudes of vectors A and B, you need to know the values of the components |Ax|, Bx, By, Cx, and Cy. Once you have those values, you can use the equations we derived in the earlier steps to solve for the magnitudes of vector A and B.