Acceleration using Airtrack E-practical
Introduction
In this experiment we are going to investigate acceleration using an AirTrack. An AirTrack is a very useful device for performing a variety of experiments about motion, forces, and momentum. What makes it so effective is its use of pumped air to create a virtually frictionless track upon which various glider configurations can be put in motion and collided against.
This picture shows you the main components.
Realistic experimental technique
E-practicals are 3d, highly realistic emulations based on a blend of theory and the actual practicals, giving an authentic experience of doing the actual practical in a laboratory. Students operate the apparatus, make measurements and obtain their own results. It is designed to reproduce the experience of performing the practical rather than simply demonstrating the underlying physics. Like a real experiment, it can be done badly. Careless setup or measurements can produce poor results, so students have to apply experimental technique and take care with their measurements.
Works directly in a browser
No installation is required. Windows, Mac and suitable mobile devices can run the WebGL e-practical.
See it in Action
This shows how the e-practical can be used. In particular it shows how the student or teacher interacts with the apparatus and how the interaction can be controlled using the mouse or the alternative on-screen controls.
What students do
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Move the position indicator on the track to about one fifth of the way along from the left, move it by scrolling when the mouse is over it.
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Raise the left part of the track using the height adjuster so that there is an appreciable acceleration when the pump is on.
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Switch on the pump.
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Make a note of how long it takes the glider to travel between the two gates, this is Dt. You may want to stop the pump at this point.
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Swap to using two independent timer gates in exactly the same positions as the two paired gates by clicking on the red cube when the glider is well out the way.
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Make sure these are both switched on and are not paired.
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Take the glider back to the same, starting and stopping the pump is a good way of moving the glider by small amounts.
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Take a note of the times through each gate, these are T1 and T2.
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The glider can be stopped by holding down the mouse button when the cursor is over the fin (the rectangular upper part). It can be released by releasing the mouse button.
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The glider can be stopped by holding down the mouse button when the cursor is over the fin (the rectangular upper part). It can be released by releasing the mouse button.
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The green track position pointer can be moved left or right by putting the mouse cursor over it and then using the mouse wheel.
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The two timers can be moved left or right by putting the mouse cursor over their bases and using the mouse wheel.
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The exact position of a timer can be accurately estimated from its shadow on the airtrack’s scale.
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Take repeated readings with different distances between the photogate timers, always starting the glider from the same position. Complete the table given in the PowerPoint.
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You should find that the acceleration is the same in all cases.
What you get
The application is supplied as a PowerPoint which provides background, a synopsis of what the student will learn, a description of the Physics involved, a description of the apparatus, the independent and dependent variables, the method, a link to the interactive online e-practical, analysis of the results and further discussion.
E-practical
Runs in a modern web browser. No software installation required. Recommended or desktops but will run successfully on tablets of medium to large size with a browser that supports WebGL.
School/Department licence £9.99
Valid for 1 year