Question

What is the direction (angle) of the resultant vector?

Rx = -419
Ry = -253
R = 490
θ = ____ ° counterclockwise from the +x-axis

Answer 1

`\theta = 148.8`

Explanation:

Given

`R_x = -419`

`R_y = -253`

`R = 490`

Required

Determine the value of
`\theta`

Since,
`\theta` is counter clockwise from x axis;

The relationship between
`\theta`,
`R_x` and R is

`cos\theta = (R_x)/(R)`

Substitute values for Rx and R

`cos\theta = (-419)/(490)`

`cos\theta = -0.8551`

Take arccos of both sides

`\theta = cos^(-1)(-0.8551)`

`\theta = 148.770784108`

`\theta = 148.8` (Approximated)