Answer 7.1a
From Mechanics
0\displaystyle \mathbf{i} + 0\displaystyle \mathbf{j},
6\displaystyle \mathbf{i} + 10.1\displaystyle \mathbf{j},
12\displaystyle \mathbf{i} + 10.4\displaystyle \mathbf{j},
18\displaystyle \mathbf{i} + 0.9\displaystyle \mathbf{j},
24\displaystyle \mathbf{i} – 18.4\displaystyle \mathbf{j}