Answer : The correct option is (A) [tex]-9.8\ m/s^2[/tex]
Explanation :
The formula is given as :
[tex]v_y=a_yt[/tex]
Where,
[tex]v_y[/tex] is vertical component of velocity.
[tex]a_y[/tex] is the vertical component of acceleration.
In a projectile motion, the particle moves in a path under the influence of gravity.
So, the vertical component of acceleration is -g i.e acceleration due to gravity.
Hence, the correct option is (a) " [tex]a_y=-9.8\ m/s^2[/tex] ".