I did an experiment to attempt to verify the Principle of Conservation of Momentum using the linear air track.
The vacuum cleaner's outlet vent is connected to the air track so that air comes up through a series of tiny holes in the track. V-shaped plastic gliders can then travel almost friction-free along the layer of air. The only problem is that getting it level so that the gliders stay in place when not moving is difficult. I think the track is slightly warped because two next to each other can drift off in opposite directions.
In the experiment, I pushed B from the right so that it travelled through the first light gate. A was stationary between the two light gates.
It stuck to A using Velcro attachments.
The two travelled together through the second light gate. The data is below.
For Conservation of Linear Momentum, the combined speed shown on the left on the screen should be half the velocity of B on its own beforehand. You can see that this worked for the second attempt.
