Experimenters· 530 nm
Sideways at constant speed, up and down under gravity: put them together and you get a parabola.
Bob
Here's a trick that makes projectiles easy: split the motion in two. Sideways, nothing pushes the ball (ignoring air), so it keeps a constant speed. Up and down, gravity pulls it at 9.8 m/s². The two parts don't interfere with each other at all.