# New Free Fall Lab

Posted on: October 3, 2012

I had been using the archaic ticker tape device to do a lab comparing acceleration to constant velocity.  Yawn.  It was not my favorite.  It wasn’t anybody’s favorite.  Let me be clear – it was boring.

I recently picked up a Sony Bloggie camera on eBay for about \$50.  It’s the same thing as a Flip camera. Make a video, flip out the USB plug, transfer file.  It’s just that easy.  I set up a backdrop of black paper from floor to ceiling.  Kids got on a desk and dropped things.  Everybody had to drop a golf ball first.  A golf ball will fall pretty close to an ideal parabola, very little air resistance over such a small distance.  After that, they could drop anything that wouldn’t break.  I have soft squeeze balls and practice whiffle golf balls, superballs and paper balls, and best of all, a coffee filter.  The coffee filter is a must, it reaches terminal velocity almost instantly.

We are using Logger Pro software from Vernier.  I suppose you could use Tracker, but I have Logger Pro and know how to use it.  In Logger Pro, we insert the movie file and then use the tools to place a dot on the object as it drops.  The software advances the frame, and in a few minutes we have a synched up video, graph and data table.  The software allows the students to quickly see how the slope of the distance vs. time graph changes.  They can replay the image and watch their data points in action.

Click for larger image

I have them use a quadratic curve fit to calculate the actual acceleration.  Then the kids create a second curve and override the fit value with g/2.  That puts the expected acceleration curve next to the actual.  The effects of air resistance are instantly visible.

We just did this lab for the first time yesterday and today.  Give the kids time, it’s going to take them a couple class periods to make this all happen.  Initial feedback has been good.  I think it’s making sense to them.  They can see the effects of acceleration.  They can clearly see terminal velocity.

Here is the lab they used.  I expect there will be some changes.

Free Fall Lab

### 3 Responses to "New Free Fall Lab"

First of all, thank you so much for your work here. I’ve been teaching Physics solo at my high school for 4 years now and have just stumbled upon this site within the last year and you have some really great ideas that I have been working on incorporating into my curriculum as much as I can with the limited resources I have.
My budget is quite thin, as many science teachers could attest but I was wondering about your Logger Pro software.
Do you have the software available through iPads? If so, is your school charged a fee PER user?
I have thought about buying the software but it would be a shame to spend my money or money from my budget on this if it wouldn’t be applicable for labs or individual use.

Here is the product site: http://www.vernier.com/products/software/lp/

The site is pretty straight forward, the software is quite good, there is a section about using it on a tablet. I’m pretty sure it is a site license, I don’t remember having any limits on where it could be installed. I wouldn’t hesitate to call them, their support is excellent.

I’m a math teacher who also teaches Physics. This is my 3rd year working with iPads. Vernier has a couple of apps which do some amazing things. Video Physics allows you to shoot a video of a falling object and then track the its flight, manually or automatically. It will give you several graphs, but the really cool thing is to copy the info into another Vernier app, Graphical. Now you can do some curve fits. I’m still learning the app (no, I don’t work for Vernier, but I do love their equipment since it works with the iPad) so I don’t know all of the in’s and out’s, but it does some really nice stuff. I have an Apple TV so I display everything on a screen. The kids are all amazed, and we have a lot of fun.

### What’s New in 2013/2014?

Every year brings a change, this one is no exception.

I will be picking up the sophomore honors Algebra II class to keep them separate from the juniors. This should help accelerate them and put them on a stronger track towards Calculus. Looks like there will be only one section each of Physics and Calculus, but still two of Robotics & Engineering.

Hot topics this year are going to be the Common-Core Standards, Standards-Based Grading (SBG), improving AP Calculus scores, and somehow adding Python, maybe as a club.

### Polls in the sidebar

Just a quick poll to help me understand who is stopping by my blog.

### Why not subscribe, it's free and I don't nag you about your clothes on the floor or the dishes in the sink.

If you are badly in need of more email or for some reason jonesing for a physics fix, enter your email address so I can bother you with my newest rant on science.

Join 314 other followers

### Blog Stats

• 1,323,860 hits by nerds like me since June 1, 2008