Similarities of Translational and Rotational Kinematics
 
Overview     
 
The equations for rotational kinematics might seem unfamiliar, but they are closely related to those for the more familiar translational kinematics.  The purpose of this experiment is to help you appreciate their similarities.  We return to the usual cart, track, and motion sensor, although this time the track is steeply sloped and connected to a vertically hanging set of masses via a string that passes over a pulley.  As the pulley turns, its rotation is sensed and sent to the computer.  We assume that the string does not slip on the pulley, but it is up to you to verify our assumption.  You will also see a meter-long thread at your lab station that will be used to determine the radius of the largest of the three pulleys on the rotary sensor.
 
You will predict the expected translational acceleration from Newton's Second Law, then experimentally determine the acceleration in four different ways, two from translation and two from rotation.  If all ways are equivalent, all five values for acceleration should be the same.

There are three parts to this experiment. Part I concerns theory, Part II, experimental preparations, and Part III, data collection and analysis. Ideally, you have tried Part I before arriving in lab so that you will have plenty of time to complete the worksheet.  If not, start with Part II.  Collect the data for Question 4 and the yellow boxes of Question 5, then return to Part I.
 
      
Far and near views of today's equipment and data
 
Part I
Part II
Part III
Worksheet
Index