We aassume the starting point is the origin. This means r0=0
The boat first accelerates to a point A say. We first must calculate the position of this point rA.
Using r=ut+21at 2+r0 with,
t=10, u=i+2j and from part a) a=0.5i−j ms−2
rA=(i+2j)10+21(0.5i−j)10 2+0