Rolling motion

Physics of the Mundane

Adam Johnston

It has been determined that all objects have a natural tendency to fall at the same rate.  Yet, when an object is rolling down a hill, its motion becomes more complicated.  Not only is such an object being pulled in a straight line down the hill, it has a tendency to rotate about some axis as it makes its way from one place to another.  It is your task to determine the extent to which this rotation affects a rolling object=s motion down a ramp, hill or other slope; and to explain what factors affect the rolling motion itself.

You should have:

C    a bunch of rolling objects (an assortment of balls, rolls of tape, various cylinders, cans of soup, etc.)

C    a selection of ramps B either ramps that have been brought to class and can be propped up with a stack of books, or a sloped walk outside the building

C    a research group of about 2-3 talented scientists, including yourself

C    stopwatches, tape measures, scales and any other necessary measuring equipment

Your task is to:

A.              Roll various objects down slopes, taking measurements to assess average velocity.  This should all be done without any injury or damage to property.  (Maybe we should shy away from bowling balls?)

B.              Determine what factor(s) (if any) determine the rate at which an object rolls down a hill.  Some possibilities might be mass, volume, roundness, color, flavor, etc.  You may have hypotheses that seem most reasonable to you.  You should begin by testing your intuition/guess/hypothesis.