The woman's average velocity can be calculated by dividing the total distance covered during the motion by the total time of the motion.
In the first part of the motion, the woman moved south with speed v1=2.00 m/s for a time of
[tex]t_1 = 60.0 m = 3600 s[/tex]
therefore the distance she covered is
[tex]S=v_1 t_1 = (2.00 m/s)(3600 s)=7200 m[/tex]
In the second part of the motion, she moved north for [tex]S_2 = 3000 m[/tex] in a time of
[tex]t_2 = 25.0 m = 1500 s[/tex]
Since she moved in the opposite direction, the total distance covered is the difference between S1 and S2:
[tex]S=S_1 - S_2 = 7200 m - 3000 m = 4200 m[/tex] (south)
While the total time of the motion is
[tex]t=t_1 + t_2 = 3600 s + 1500 s =5100 s[/tex]
Therefore, the woman's average velocity is
[tex]v= \frac{S}{t}= \frac{4200 m}{5100 s}=0.824 m/s [/tex] (south)
and the correct answer is A).
