Physics - Kinematics Question with Solution | TestHub

For minimum time the motorcycle accelerates to a peak speed $v_m$ and then brakes to rest. With $v_m=10t_2$ from the braking side and $v_m=5t_1$ from the accelerating side, $t_1=2t_2$. The area under the $v$-$t$ triangle gives $\frac{1}{2}(3t_2)(10t_2)=1500$, so $t_2=10$ s, $t_1=20$ s and the total time is $30$ s. Option D.