Question

Can gravitational acceleration be written as velocity*sin(theta)/time (if velocity is very small)?

Answer 1

i have no idea.

Answer 2

Considering vertical component of projectile motion

y' = vsin(theta) - gt
As y' -> 0 (which technically if when maximum height is reached by a projectile with some upward component) vsin(theta) --> gt so g --> vsin(theta)/t (exactly when y' = 0)