What are all the entities that move in a parabola/line?
Solution 1:
Nearly all entities can be moved in a straight line, just not very far. Dropping an object, shooting it from a dispenser, or bouncing it off a slime block will move the entity a very short distance (often less than one block) in a straight line.
Other entities that move in larger parabolas would include a fishing rod hook or TNT launched from a TNT cannon.
Most mobs can be moved by explosions, which throws them from the blast in a parabolic line outwards
Falling sand, gravel, or anvils also fall in a straight line directly downwards