Objectives

1. Make a video of a spinning object
2. Track the motion of points on the object at different radii from the center of rotation
3. Compare the linear and angular velocity of points at different radii

Resources

• Rotating table
• Masking tape
• Phone or digital camera
  • High-speed Motion Capture with Casio Exilim Camera
• Tracker Software
  • Quick Tutorial on Tracker

Background

Points on solid object rotating around a fixed axis all move in circular paths. The angular velocity in radians per second of all points on the object is 2\pi/T, where T is the rotation period. The velocity of points a distance r from the center of rotation is v=\omega r

Analysis Questions

1. Plot the linear velocity vs. radius for points on the wheel and determine the slope of a linear fit to the datapoints to determine the angular velocity of the spinning table.
2. Calculate the period of the wheel’s rotation from your video and compare the resulting angular velocity to the one from your plot.