Concepts

Damped harmonic motion, eddy currents

Overview

A magnetic mass hangs on the end of a swinging rod. A movable copper plate damps the oscillations. The rod is connected to a rotational motion sensor, which can transmit the data to a computer for graphing.

Details

Equipment

• [1] Steel mass on a rod
• [1] Rare earth magnet
• [1] Copper plate on a wooden block
• [1] Rotational motion sensor and rod-mounting hardware
• [1] Aluminum rod
• [1] 90-degree clamp
• [1] Lab stand
• [1] LabPro interface with AC adapter and USB cable
• [1] Computer with Logger Pro

Classroom Assembly

1. Turn on the computer and start Logger Pro.
2. Put the magnet on the steel mass.
3. Mount the rod on the rotational motion sensor.
4. Mount the rotational motion sensor on the lab stand using the aluminum rod and 90-degree clamp.
5. Connect the LabPro interface to the rotational motion sensor, the computer, and power.
6. Set up and test the sensor in Logger Pro.

Script

1. Start the pendulum oscillations and start data collection.
2. Change the damping by altering the magnet-copper separation and repeat.

Additional Resources