1.What is the acceleration of a projectile when instantaneous vertical velocity is zero at the top of its trajectory?
2 answers
The acceleration is always -g, in the downward direction if distance is measured positive upwards.
it depends... when you talk about acceleration of object going downward, its -g... when acceleration going up, example an object is thrown, i think its 0.
ax=o; ay= -g
ax=o; ay= -g