A ball is thrown up with initial velocity $u$. It reaches its highest point at time:

1. Rising motion follows $v=u-gt$, with $g$ opposing the upward velocity. 2. At the highest point the ball is momentarily at rest, so $v=0$. 3. Substituting gives $0=u-gt$. 4. Rearranging, $t=\dfrac{u}{g}$. 5. The value $\dfrac{2u}{g}$ is the total time of flight, since the fall takes as long as the rise. _Source: NECTA CSEE 2021 Physics 031, Question 1: Multiple Choice, item (iv)_