The new Go Direct® Centripetal Force Apparatus makes it easier than ever to investigate rotational dynamics. Students can investigate the relationships among force, mass, and radius wirelessly—all you need is the Go Direct Centripetal Force Apparatus, a Go Direct Force and Acceleration Sensor, and a device running our free Graphical Analysis 4 app. No additional interface is needed.

With Go Direct Force and Acceleration mounted on the apparatus’ beam, you are ready to investigate centripetal acceleration. Attach the mass carriage, and you can explore Newton’s second law as it applies to rotational dynamics. No tangled wires to worry about. All you need to do is slide the sensor onto the beam, attach the mass carriage, and secure the sensor at the desired location. Select the appropriate data-collection channels in Graphical Analysis 4 for your investigation: Z-axis gyro to capture angular velocity, X-axis acceleration for centripetal acceleration, and/or Force for centripetal force. Then, you’re ready to collect data. As you turn the spindle to rotate the beam, the sensor will apply the force necessary to pull the carriage in a circular motion.

Applying a curve fit to the raw data will provide students with clues to nature of this relationship.

The relationship can be further explored as students apply knowledge gained from the curve fit to linearize the data.

Linearized data for a rotating mass. What are the units of the slope of the line? Can your students predict the mass given the position on the beam?

Students can quickly devise their own experiments to develop a model for the effect of mass or radius of rotation on the force, and then test the model. Select a mass and position and see if it matches their prediction.