The
co-ordinates have to be the same in order for something to be due south of something.
Thus, we have to see, how long it takes for the
co-ordinates to become equal.
Thus, we got that the speed is
So, the
co-ordinate of A is
.
Thus,
The total time to get to the point
is 7 seconds,
.
Thus you simply add the new value to
. And you get the answer: