Meriam, Kraige & Bolton — Kinematics of Particles: Problem 2_192

2/192 A particle moving in the $x$-$y$ plane has a velocity $\mathbf{v} = 7.25\mathbf{i} + 3.48\mathbf{j}$ m/s at a certain instant. If the particle then undergoes a constant acceleration $\mathbf{a} = 0.85\mathbf{j}$ m/s², determine the amount of time which must pass before the direction of the tangent to the trajectory of the particle has been altered by 30°.