Vernier Tech Info Library TIL #1298

Question

How short an impulse can I measure with the Force Plate?

Answer

The Force Plate, like any sensor, has a limit to how quickly it can respond to a change. If a very short impulse is applied to the force plate, it will vibrate, or ring, for a short while. That ringing frequency is in the neighborhood of 250 Hz, with a period of about 4 ms. Any impulse with a duration shorter than 4 ms will only produce the ringing; there is no way to resolve anything shorter than that. Even an impulse with a time of 10 or 20 ms will be distorted by the finite response time of the force place. In order to really see the structure of an impulse, it would have be longer than 20 ms or so--ten times that would be a reasonable limit to get useful data.

This means that you could bounce a soft, squishy ball off of the plate and see the details of the impulse, but you can't possibly get useful data for the impulse of a baseball or a golfball on the plate.

Created by: jgastineau on May 28 2004
Last updated by: gretchen on August 19 2005