Objects are slowed down by [blank_start]air[blank_end] [blank_start]resistance[blank_end].
Once [blank_start]air[blank_end] [blank_start]resistance[blank_end] is equal to the force of [blank_start]gravity[blank_end], the object has reached [blank_start]terminal[blank_end] [blank_start]velocity[blank_end].
This means that it will stay at a [blank_start]constant[blank_end] [blank_start]velocity[blank_end].
The acceleration of [blank_start]free[blank_end] [blank_start]fall[blank_end] for a body near to the Earth is [blank_start]constant[blank_end]. [[blank_start]g[blank_end] = [blank_start]10m/s^2[blank_end]]