Chapter 4
Newton's Three Laws
Part 3

Solution for Example 2

First we need to resolve the vectors into component vectors along the horizontal and vertical directions.

First we need to add up all of the forces in the y-direction.

Since the vectors are all in the same direction, we can add up the scalars of these vectors.

Using the angles and the magnitudes of the vectors and the fact that the third vector is along the y-axis you get the equation:

Therefore, the sum of the y-components of the vectors is zero.

Now, we do the same for the x-direction. Here the third vector is zero in the x-direction.




This also give us zero in the x-direction. Therefore, the final force is .

Since, the final force is equal to zero the vectors must add up to zero and form a triangle.

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