At time t t\,t seconds, where t≥0t \ge 0t≥0, a particle P P\,P moves so that its position vector r m\mathbf{r} \text{ m}r m is given by r=(t2+6t)i+8tj\mathbf{r} = (t^2 + 6t)\mathbf{i} + 8t\mathbf{j}r=(t2+6t)i+8tj.
Show that the velocity of P P\,P is (2t+6)i+8j(2t + 6)\mathbf{i} + 8\mathbf{j}(2t+6)i+8j
Find the value of t t\,t at the instant when the speed of P P\,P is 10ms-1
363 exam-style questions on Edexcel A Level Maths Further Kinematics, covering 8.1 Vectors in Kinematics, 8.2 Vector Methods with Projectiles, 8.3 Variable Acceleration in One Dimension, 8.4 Differentiating Vectors, and 8.5 Integrating Vectors. Each one has a worked solution and a mark scheme showing where the marks go.