text: # Objects A and B are at the origin. If object A moves to (3 ,-4 ) and object B moves to (2 ,-6 ) over 4 s, what is the relative velocity of object B from the perspective of object A?
  
  Mar 21, 2016
  
  $\text{watch over the animation}$
  ${v}_{\text{AB"=sqrt5/4 " unit/s}}$
  
  #### Explanation:
  
  $\text{displacement for the object of A and B:}$
  $\Delta s = \sqrt{{2}^{2} + {1}^{2}}$
  $\Delta s = \sqrt{5}$
  ${v}_{\text{AB}} = \frac{\Delta s}{\Delta t}$
  ${v}_{\text{AB"=sqrt5/4 " unit/s}}$