If you attempt to collect data for an inelastic collision (using the lumps of clay on the bumper launcher kit) you may find it difficult to balance getting adequate force data and meaningful velocity data from the motion encoder.

This is only an issue when collecting data with the LabQuest App. Logger Pro has a process called “undersampling” that corrects this.

At 50 samples/second (default sampling rate) the rate is too slow to capture the force data during the collision. Anything above 100 samples/second results in noisy velocity data from the motion encoder.

Here are some suggestions for getting good data with an encoder cart and force sensor using the LabQuest App:
1. Set the sampling rate to 100 samples/second
2. Knead the clay so that it is very soft and shape it into a very long cone, in order to slow the collision.
3. Push the cart gently to get a velocity around +/-0.40 m/s

When using the integral tool to determine the impulse, be sure to include any “bounce” that occurs before coming to a complete stop.

Motion Encoder System Troubleshooting and FAQs