After 0.3 seconds,
Horizontal distance, dx = 10
Vertical distance, dy = 8
The horizontal velocity, vx would always be constant
The vertical velocity, vy would change as the object moves upwards and comes own
horizontal velocity, vx = displacement/time = 10/0.3 = 33.33 m/s
vertical velocity, vy = 8/0.3 = 26.67 m/s
Recall the formula for motion,
v = u - at
a = acceleration
t = time = 0.3
v = final velocity = 0
u = initial velocity = 26.67
By substituting these values, we have
0 = 26.67 - a x 0.3
0.3a = 26.67
a = 26.67/0.3
a = 88.9 m/s^2
The acceleration of freefall is 88.9 m/s^2