At 2 p.m. drone P P\,P has position vector (2i+7j)(2\mathbf{i} + 7\mathbf{j})(2i+7j) m and moves with constant velocity (i−2j)(\mathbf{i} - 2\mathbf{j})(i−2j) m s−1\text{s}^{-1}s−1. Another drone Q Q\,Q has position vector (−3i+j)(-3\mathbf{i} + \mathbf{j})(−3i+j) m and moves with constant velocity (5i+2j)(5\mathbf{i} + 2\mathbf{j})(5i+2j) m s−1\text{s}^{-1}s−1.
Find the relative displacement of drone P P\,P from drone Q Q\,Q after t t\,t seconds.
Find the time when P P\,P is due west of QQQ.
Find the time, after 2 p.m., when the drones are exactly 85 \sqrt{85}\,85 m apart.
