SCIENCE

PHYSICS IN ACTION: WHEN AIR HOCKEY MEETS DODGEM CARS!!

Take a surface that runs like an air hockey table, and two objects that can bounce off each other like dodgem cars, what do you get? 

Answer: An opportunity to explore the fundamental rules of nature, and heaps of fun!

Because in our world, friction is everywhere, almost all motions of every day’s objects look more complicated than they really are. To minimize this effect, the same concept used in an air hockey table can be applied to create a long smooth track on which specially built carts can be made to “float” on top. Using such linear air tracks, an almost friction-free environment for exploring impulse, momentum and kinetic energy can be obtained.

In a recent senior Physics class, students undertook a practical investigation of collisions using one of these linear air tracks. Such concepts inform the design of a diverse array of technologies from automotive safety systems such as crumple zones, air bags and seat belts, to rackets, bats, balls and other sporting equipment. 

One of the highlights was exploring collisions on the air track, where students observed how kinetic energy and momentum behaved before and after collisions. Two pairs of light gates connected to digital timers separated by controlled distances allowed for very precise estimates of velocities, and the bodies involved had their masses determined to within 0.01 grams. Subsequent calculations evaluated the correspondence to the predicted relationships and the underlying assumption about the isolated nature of the system. 

This practical investigation not only deepened their understanding of physics but also honed their critical thinking and experimental skills and provided links to key applications of the theories in industry.

Mr Grantham-Smith & Dr Law

VCE Physics Team

PHYSICS STUDENTS’ REFLECTIONS

The air track conservation of momentum experiment was an eye-opening experience, I got the chance to push one of the carts along the track and see it bump into the other cart. We got to see how the rules we learnt in physics apply to real-life situations. 

Helen Chen, Year 12

The physics practical investigation served as a pleasant break from theoretical calculations usually performed in the classroom. I found the collisions particularly enticing, they truly reminded me about the exciting nature of physics and motion. We also as a class were able to discuss the limitations of the experiment and possible improvements. It’s thanks to excellent teachers such as Mr Grantham-Smith and their dedication to the physics students like me are able to find a passion in the field of STEM!

Antonina Mikhaylova, Year 12

This experiment was really enjoyable and unique to what we’ve done in physics before. I’d never been lucky enough to be able to use the linear air track before, so to finally be able to operate it was definitely a highlight. Despite some initial hiccups with the carts launching off the track, the experiment helped me visualize how momentum is conserved within a (nearly) isolated system, aiding in my understanding of my favourite subject, physics!

Ross Rogerson, Year 12

In physics, we recently conducted an experiment observing the conservation of momentum. By colliding two objects together on an air track, while recording the velocity using photogates, we saw that momentum was conserved by the objects. It was a very enjoyable experiment. 

Jack Sweeney, Year 12

The experiment was so much fun, I was eager to come to class that day knowing we were conducting one of the best physics experiments ever. Nothing compares to physics experiments with Dr Law and these types of experiments are the reasons why everyone should do physics.

Joshua Strunin, Year 12