One of the biggest advantages of interface equipment is that it allows students to get very accurate data for experiments where collecting good data by traditional means is very difficult.
Take for instance, momentum transfers - tracking the momentum of objects pre- and post collision can be challenging. But not if you have some good interface equipment!
The students in the video (QuickTime 1.2 MB - just click the play button!) below were performing two experiments - a completely inelastic and a completely elastic collision. The inelastic collision is aided by carts that have small bits of velcro on the ends, so that they stick and move off together post-collision. The elastic collision is aided by carts that have built-in magnets that repel. The velocity of the carts is tracked with motion sensors that are part of the Pasco Science Workshop system.
It's hard to see the results on the screen in the video, so I saved some screenshots - the following one shows the motion sensor position-time data as the cart moves away, strikes the other cart, then moves off stuck together.
What's great about the DataStudio software is that students can apply a linear fit to different parts of the curve and find the velocity of the cart(s) (see the slope value).
Here's a few more screenshots;
Screenshot A shows a linear fit on the post inelastic collision, and screenshots B and C show the before and after collision linear fits on carts involved in an elastic collsion. Students are then required to calculate and compare momentum before and after. The results are amazing... students will often show me calculations that have only a few one-hundreths difference in pre- and post momentum values. I highly recommend this experiment!
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