Astring runs up and to the left in thex⁢yplane, making an angle of 39 degrees to the vertical. determine the unit vector that points along the string.

Explanation:

Vectors

It's an element that has both magnitude and direction. It can be geometrically represented as a directed line segment whose length is the magnitude and the arrow points in its direction. There are several ways to mathematically represent a vector. The most commonly used are in the polar and rectangular coordinates. In the polar form, a vector has a magnitude and an angle measured respect to the horizontal right direction. It's written as . The rectangular representation has the two coordinates (x,y) measured in the known plane xy. The conversion between both systems is

A representation of the vector is shown in the figure below. The angle of is measured respect to the vertical, we must add to make it compliant with the standard expressions of vectors. We have r=1,

The unit vector is

Or equivalently

f=ma newton's second law 7x8=56n