PURPOSE:
To expose the student to new equipment and lab procedures. And to calculate the acceleration down an inclined air track.

INTRODUCTION:
Acceleration can be calculated in several different ways in this lab. 1) By the change in velocity that an object undergoes during a measured time, 2) By the force a measured mass displays and 3) By knowing the angle at which gravity is deflected. During the lab you will adjust the angle of an inclined air track and see the effect this angle has on acceleration due to gravity. An air track is used to eliminate the effects of friction on our object and photogates are used to measure the passage of time.

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A 'inclinable' air track will provide a setting that is almost friction free.

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A pair of "photo-gates" and monitor are provided to time the passage of the carts on the air track.

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If you get into trouble and perform some procedure that causes the lab to fail(lab equipment will no longer operate), you can press the "Reset" button and the simulation will return to the starting position.

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PROCEDURE:

1) You can adjust the background shading by clicking on the "Special" button to the right and selecting "Background". Click on the "Special" button and select "Print Blank Report" to obtain a web page that can be printed and used as a lab report. (the program will not be interrupted)

2) Drag the cart that is located on the air track and at the same time press the "p" key. This will allow you to remove the cart and place it on the electronic balance on the table. Record the cart's mass. Return the cart to the air track.

3) Drag the ruler, on the table, up to the cart. Record the length of the cart. Caution: the ruler is in cm and the value should be recorded in meters.

4) Drag the cart over near photogate 1(PG1). The photogate is the device with a blue base and a rod with a square top. Turn on PG1 by clicking on the button on the left side of its base. The sensor eye should glow green. Drag down the sensor eye until it is at the same height as the card on top of the cart. This sets the eye so that it will measure the card as it passes by. Do the same for PG2. Turn on the photogate monitor, TV looking object on the table, by clicking on its On/Off button.

5) Drag the cart all the way to the right until it clicks in place. The cart must be "locked down" in this manner in order to change the angle of the air track. Click on the "Angle Control" located in the lower left of the screen, and make the air track start to angle down to the left. There is an angle indicator (blue) hanging from the bottom of the air track, use this to set the angle of the track to 10 degrees.

6) Turn on the air blower canister, on the table, by clicking on its green button. You should hear the air being produced by the device. Air is forced into the hollow air track and is released through the holes that line the track. The cart covers these holes with a flat plate on each side of the track. The pressure of the air lifts the cart off of the track and allows it to move without any friction (actually so small we can ignore it).

7) The 10 degree incline run is ready to start. Click on the red lever to the right of the air track.

8) As the cart passes the photogates, the monitor will display the time it takes for the card atop the cart to pass the photogate light emitter. It will also measure the time it takes to move from one photogate to another (listed as PG1-PG2). Record these three values.

9) While the air is still on, drag the cart half way up the air track and hold it there. At the same time press the "s" key and a newton scale will appear and measure the force that the cart is pulling with. Record this force.

10) Release the cart. Perform this same procedure with the air track set for 20 degrees and 30 degrees, recording the same values as taken in the 10 degree run.

11) Calculate the requested values asked for on the lab sheet and any given by your teacher. For help on these values click on the "Special" button and select "View Data & Hints". Select "File Report" to send a copy to be viewed by your teacher.