As you watch this video, try to spot the hidden arithmetic and quadratic number series.

Answer

A ball rolling down an incline has a constant acceleration of gsinθ.

Because the acceleration is constant,

the velocity increases linearly with time (v=at), and

the displacement quadratically with time (s=½at^{2})

In addition, because the motion starts from v=0 at t=0, the (a) velocity, (b) distance travelled per unit time, and (c) total accumulative distance travelled, all form very nice number series.