Answer
The vertical component $v_y$ of the particle’s velocity is greatest in magnitude at $\theta = 0^{\circ}$ and $\theta = 180^{\circ}$
Work Step by Step
The speed of the particle is constant.
At $\theta = 0^{\circ}$, the velocity vector is directed straight up, so the magnitude of $v_y$ is a maximum.
At $\theta = 180^{\circ}$, the velocity vector is directed straight down, so the magnitude of $v_y$ is a maximum.
The vertical component $v_y$ of the particle’s velocity is greatest in magnitude at $\theta = 0^{\circ}$ and $\theta = 180^{\circ}$
