Rolling friction is generally small. How can we measure it? Does it work the same as other friction?

We tried the following: we rolled a cue ball through a pair of Vernier photogates, and then measured the distance from the gates to where the ball stopped.

gateTime

is the time in seconds between the time the ball interrupted the beam on the first gate and the time it interrupted the beam on the second. The distance between the beams is 15 mm.

distance

is how far the cue ball traveled, measured in centimeters from the gap between the gates to the end of the cue ball (diameter: 5.5 cm).

cue_or_roll

describes how the ball was sent, and any unusual occurrences

What is the relationship between gateTime and the speed of the ball?

Are the data consistent with uniform deceleration? (They are, more or less. How do you show that?)

What could explain any inconsistencies?

What is a reasonable value for the coefficient of rolling friction in this setup? Do you need the mass of the cue ball?

Find references to this quantity on the web. Is your coefficient comparable?

(data by Bryan Cooley, January 2003)