Experimental setup for Projectile Motion

A typical high school science student in India studies kinematics for about a month. And yet there is no lab experiment to go along with the theory. Wanting to remedy this, I designed an inexpensive projectile motion experiment. The setup has been replicated and is being used to train high school science teachers at the Talent Development Center, IISc. The project was also published as a technical article in Resonance journal.

An Experiment on Projectile MotionAmitabh Shrivastava, MK Raghavendra, KP Ramesh
Resonance ISSN 0971-8044, v. 20, no. 5, p458, May 2015

As with many of my projects, this one was inspired by the desire to learn – in this case Arduino. I discovered arduino through an exhibit at IISc’s open day. And wanting to give back to the educational community might have had something to do with it as well.. In any case, the day I discovered arduino, I reached out to my friends and borrowed a duemilanovae. I was well versed with programming and analog circuits, so this was somewhat familiar terrain. In the coming weekend, I made a heart rate sensor using IR LEDs (both as a source and as a sensor – yeah you can do that!). I was surprised at the rate at which I could read analog values and this inspired me to measure the speed of my coil gun. From there on, the idea of projectile motion came pretty much fully formed. I approached my physics lab instructor Dr. Raghavendra and he was happy to fund the project.

The bulk of the initial work in the project was to make the unit standalone, not needing a laptop to function. So I had to gain a lot of knowledge very quickly to store and recall data, add a display, correct for lag in the code, and test the code to be robust against user inputs. Once a prototype was ready and the code was tested I had to make an enclosure and write a small manual for the unit.

projectile-launcher
A de-soldering pump mounted on a graded plate, used as a projectile launcher.

I would like to thank Dr. M K Raghavendra and Dr. K P Ramesh for funding and helpful comments.