Question

Find the magnitude of the vector -34 i + 15 j m, and determine the angle it makes with the +x axis. Which one is the angle it makes with the positive x axis? thank you):

Answer 1

The magnitude of a vector is the root of the sum of the squares of each component. In your case, the magnitude = sqrt[(34)^2+(15)^2] = 37.16 m. The angle it makes with the X-axis is the tan inverse of the ratio of the y-component to the x-component. Therfore, angle = tani(15/-34) You can evaluate that value :)

Answer 2

from the figure tan(theta)=15/34;
but we want the angle made by the vector with positive x axis ,so required angle is equal to 180-theta