Question 683891
The route taken by the boat is a right angle
so the actual distance from starting point is any point of the hypotenuse

d(east)= 30 mi
d(south)=10 mi/h
After2 hours it would be 20 miles down south

distance from origin = sqrt(30^2+20^2)  ( the legs of the right triangle)

After 2 hours it is sqrt(1300) from the origin

its rate with respect to origin = d/t
sqrt(1300)/2

10sqrt(13)/2
5sqrt(13) mi/h is the rate with respect to origin P after 5 hours.