Central Forces: Motion in Two Dimensions
Ball on a String
PIRA Class: 1D50.10
Purpose
To observe a centripetal force & the resulting circular
motion
Description
Variation 1: Twirling a ball in an overhead horizontal orbit,
release ball from its revolution to see the subsequent path flight.
Variation 2: Grasping hollow tube, swirl ball overhead at a
rate such that the weight of the washers provides an adequate centripetal force for a
controlled orbit.
Variation 3: Measure the radius of the orbit of the ball,
time 10 revolutions to determine the average time of revolution, and calculate the linear
velocity of the ball. Graph v vs. r
EXTRA: With a constant downward pull on the washers, show the
resulting increase in the velocity of the orbiting ball
Equipment
Ball on a String: Rubber ball and washer weights are tied to
opposite ends of a string laced through a hollow glass.