The Universal Arc

Throw a ball, fire an arrow, launch a cannonball — they all trace the same shape: a parabola. This is not coincidence. It is gravity doing the same thing to every object regardless of what it is.

Once a ball leaves your hand, nothing pushes it forward. It coasts horizontally at constant speed while gravity pulls it down with increasing speed every second. Combine those two independent motions and you get a curve — always a parabola.