title: Given the x and y components of the velocity, how can the angle be computed?
body: <p>For a particle moving about in a Cartesian coordinate system (neglecting the z-axis), how can the angle of travel be computed given the x and y components of the velocity? </p>
  
  <p>Before anyone says this isn't programming related, I am programming this right now, however, I don't know vector math.</p>
  
  <p>For example, suppose the x and y values of the velocity are respectively 5.0 and -1.5, how would I compute the angle?</p>