A particle P P\,P of mass 0.8kg moves under the action of a force F F\,F N. The acceleration of P P\,P is (−3i+5j)(-3\mathbf{i} + 5\mathbf{j})(−3i+5j).
Find the angle between the acceleration and the vector i\mathbf{i}i.
Find the magnitude of FFF.