What you're seeing

On the left, the ball falls past a height scale. A dot marks where it was every half second. On the right, two graphs build up as it falls: its speed and how far it has fallen, both against time.

Why the dots spread out

Every gap is the same amount of time. A bigger gap means the ball covered more distance in that half second — it was going faster. The gaps keep growing because gravity keeps speeding the ball up the whole way down.

Reading the graphs

The speed graph is a straight line: the ball gains the same amount of speed every second. The distance graph curves upward: each second it falls farther than the second before.

Things to try

Drop on Earth, then switch to the Moon and drop again. Earlier drops stay on the graphs in grey so you can compare. Which line is steeper? Which ball takes longer to land? Try Jupiter with Slow motion on.

Change the height. Does a higher drop make the speed line steeper, or just longer?

What this leaves out

There is no air here. In real air, a ball dropped from this high would land noticeably slower than shown, and a feather would barely fall at all. With no air, every object falls exactly like this ball.