A particle P P\,P of mass 0.8 kg moves under the action of two forces only, F1=(7i+3j)\mathbf{F}_1 = (7\mathbf{i} + 3\mathbf{j})F1=(7i+3j) N and F2\mathbf{F}_2F2 N, where i\mathbf{i}i and j\mathbf{j}j are perpendicular unit vectors in a horizontal plane.
P P\,P moves with constant acceleration (2.5i−5j)(2.5\mathbf{i} - 5\mathbf{j})(2.5i−5j) m s−2^{-2}−2.
Find the magnitude of F2\mathbf{F}_2F2, and the angle between F2\mathbf{F}_2F2 and i\mathbf{i}i.
139 exam-style questions on AQA A Level Maths 3.3 R: Forces and Newton's laws, covering 3.3.1 Concept of a force and Newton's first law, 3.3.2 Newton's second law, 3.3.3 Weight and motion under gravity, 3.3.4 Newton's third law and equilibrium, 3.3.5 Addition of forces and resultants (A-level only), and 3.3.6 Friction (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.