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.