3A60.24 Driven Cart Oscillator
A wheeled cart with springs attached is driven by a motor that is controlled by a variac. A motion detector connected to a computer helps graph the cart's motion.
-  Variac
-  DC motor
-  Cart with motion detector plate
-  Track
-  Spring
-  Small magnet
-  Motion detector with post attached
-  USB A-B cable
-  Lab stand
-  90-degree clamp
-  Computer with Logger Pro (Windows or Mac OS)
- Connect a DC motor to the variac and position the motor such that students can see the rotation of the motor clearly.
- Add as many damping magnets to the cart bottoms as desired.
- Start with voltage at zero volts to begin.
- Start up the computer.
- Attach the cart to the plate.
- Hook the springs to the cart and the track.
- Mount the motion detector to the lab stand and position it to view straight down the track.
- Connect the computer to the motion detector using the USB cable.
- Start Logger Pro and make sure that the detector captures the cart's full range of motion.
- Increase the voltage carefully, be sure not to apply a voltage larger than 100 volts.
- If cart oscillations are too strong, add more magnets to the undersides of the carts.
- Knowledge of Logger Pro is essential.
- If the graph of cart motion clips at the high or low ends, try raising the motion detector or removing objects near the track.
- Connect the springs and the cart as shown on the image, if they are not already connected.
- Attach the spring to a screw at the end of the track.
- Connect the spring to a motor by a string.
- Turn on the variac and slowly increase the voltage.
- Put a 250g mass on top of the cart to increase the mass of the cart if necessary. Note that the mass of the cart is approximately 250g.
- Start the data collection.
- Go to a different page in the Logger Pro file for other measurements.
- PIRA 3A60.24
- Don't attempt this at home!
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.