Class Setup for Activity 9

[Jeff Briggs]

  For this activity, we had one standardized lab setup that each group could use in turn to determine the effect of their 'cushion.'  I used Vernier probes and a Labpro interface to a PC running Logger Pro software.  We strapped the a Dual Range Force probe to the table to minimize its own motion and then released the Pasco carts down a standard incline from a set height to hit the probe.

  With no cushion, the force spike was short and large.  Logger Pro allows you to see the force vs time graph as soon as it happens.  Without going into detail about the impulse being force x time, the students still were able to see that as they added cushioning material the max force reached changed significantly from the no padding test.  The graphs of force vs time showed them that it wasn't magic - simply good physics in stretching the collision over a larger time period, the max force was reduced, therefore increasing the survivability of the crash.

  This is the first year that I have tried the Logger Pro software and I like it a lot.  I also like the fact that for the price of one copy, they allow you a site license on all school computers (and home computers of students involved).  Disclaimer:  I have no financial interest in Vernier... but I do like their stuff.  If you have Pasco or other brand, I'm sure that would work well here too.