What is the acceleration of a projectile fired vertically upwards? Is it positive or negative?

Vertically downwards?

3 answers

gravity always accelerates objects toward the center of the Earth
That is what I was thinking. I just was not sure if firing the object made a difference.
Either way it's -9.8m/s2 since it is slowing down due to the acceleration of gravity if thrown upwards. The same with vertically downwards, it's accelerating downwards -9.8m/s2 due to the acceleration of gravity.