The nice thing about computer technology in the science lab is that interfaces, probes and software can tame previously difficult to measure phenomenon.
Take for instance the determination of a vehicle's kinetic energy at a particular point, or the conversion of potential to kinetic (yeah, I know, the potential energy is not the hard part!). With the help of a nearly frictionless dynamics track and some dynamics carts, we can run many trials in just minutes.
In this lab a cart is fitted with a "picket fence", to provide a dark area for a motion sensor to read:
Pasco provides some neat accessories with their carts, in this case, a 500 g removable mass that fits nicely on the cart, so that students can easily run trials with different masses (so as to confirm if mass matters for falling objects).
Students place the cart on an inclined track, and near the bottom the cart passes through a photogate which determines the cart's speed at that point:
Since the DataStudio software allows for calculations, not just raw measurements, the time in the gate can be converted into a speed in metres/second:
When this calculation is reported in a table, and students run multiple trials, the data look something like this:
After running a few trials, students take the mean measure of speed and use it for their kinetic energy calculations (if you wanted to, you could add the mass of the cart to your calculations and have the KE reported directly!)
Here's a short QuickTime movie of a student running some trials - it's so easy!
The nice thing about the whole lab is that a whole classroom full of students can run through the lab, conducting multiple trials with different masses, and be complete in about 25 minutes - cool!
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