To calculate the speed and velocity of the Ann`s we use the formula,
[tex]v= \frac{d}{t}[/tex]
Here, d is distance and t is time and v if we take it with direction then it is called velocity and if we take it without the direction then it is called speed.
Given [tex]d=1.5 miles[/tex] and [tex]t=0.5 hours[/tex].
Substituting these values in above equation we get
[tex]v=\frac{1.5mi }{0.5 h} = 3 mi/h[/tex]
As Ann walked towards south direction therefore, Ann`s velocity is 3 mi/h south and her speed is 3 mi/h .