Answer:
θ = 122°
Explanation:
Components of a Vector
A vector in the plane can be defined by its rectangular components:
[tex]\vec A =<x,y>[/tex]
Or also can be given by its polar components:
[tex]\vec A =<r,\theta>[/tex]
Where r is the magnitude of the vector and θ is the angle it forms with the positive direction of x.
The relation between them is:
[tex]r=\sqrt{x^2+y^2}[/tex]
[tex]\displaystyle \theta=\arctan\frac{y}{x}[/tex]
It's given the x-component of vector A is x=-25 m and the y-component is y=40 m
(a)
The magnitude of the vector is:
[tex]r=\sqrt{(-25)^2+40^2}[/tex]
[tex]r=\sqrt{625+1600}[/tex]
[tex]r=\sqrt{2225}[/tex]
[tex]r\approx 47.2\ m[/tex]
(b)
[tex]\displaystyle \theta=\arctan\frac{40}{-25}[/tex]
[tex]\displaystyle \theta=\arctan (-1.6)[/tex]
The calculator gives us the value
θ = -58°
But the real angle lies on the second quadrant since x is negative and y is positive, thus:
θ = -58° + 180° = 122°
θ = 122°