A vector has an x component of -5.51 units and a y component of +9.52 units. The angle between the positive direction of the vector and the positive direction of the x-axis is A) 125^o. B) 60^o. C) 120^o. D) 150^o. E) -60^o.

Question

Quizplus · Accepted Answer

Using the tangent function: 
tan(theta) = (y-component)/(x-component) 
tan(theta) = (9.52)/(-5.51) 
theta = tan^(-1)(-9.52/5.51) 
theta = -120° 
Since the angle is measured from the positive x-axis, the answer is 120°.

A Vector Has an X Component of -5