Ball Drop On Rope - Equal And Unequal Intervals

Purpose

To illustrate the geometrical effect of free fall.

Equipment

Two nylon ropes with attached steel balls, as photographed.

Suggestions

Drop balls on wooden sounding board to amplify the sound.

Images

c2-06

Description

Two ropes of equal length have steel balls tied at five points along their length. One rope has the balls at equal distances along the rope, while the second has balls positioned geometrically, at distances proportional to the squares of integers: 1, 4, 9, 16, and 25. When the first rope is dropped the equally spaced balls hit the floor at progressively shorter time intervals; when the second rope is dropped, the geometrically positioned balls hit the floor at equal time intervals.

References

(PIRA 1C20.20)