Question

in the formula $v_y = a_ydelta t$, what is the value of $a_y$ for an object in projectile motion?
-9.8 m/s²
0 m/s²
$\frac{1}{2}$ m/s²
1.0 m/s²

Explanation:

Step1: Recall projectile - motion acceleration

In projectile motion near the Earth's surface, the acceleration in the vertical direction is due to gravity.
The acceleration due to gravity near the Earth's surface has a magnitude of approximately $9.8\ m/s^{2}$ and acts downwards. In the standard coordinate system where up is the positive $y -$ direction, the vertical acceleration $a_y$ is negative.
So, $a_y=- 9.8\ m/s^{2}$.

Answer:

-9.8 m/s²