General Physics Lab: Velocity and Acceleration

Equipment and setup

• The experiment has three parts: (1) study constant velocity with a level air track (Figure 1), (2) study constant acceleration with an air track inclined with a stepping block (Figure 3 and 4), and (3) determine the acceleration due to gravity of a free-falling picket fence (Figure 6).
• All experiments use a photogate attached to the LabPro computer interface (Figure 1). As the picket fence passes through the photogate, the LabPro sends data to the computer and the picket fence's time, position and velocity are displayed (Figure 2).
• The data can then be stored in an Excel spreadsheet and graphed.
• The elevation of the stepping block is measured with a vernier caliper (Figure 3). The separation of the air track's legs is measured with a meter stick (Figure 5).
• The air blowers in room (219) are located below each lab table (Figure 7). When the experiment is conducted in room 221, the air blowers will be found on the table top.
[Click on images to enlarge.]
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TA Notes
• Perform the experiment ahead of time!
• Don't allow the gliders to crash in to the air track stops.
• Please make sure that students place the glider on the air track only after the air blower has been turned on.
• Adjust the height of the photogate so the picket fence passes easily though it.
• When making a Velocity vs Time graph, make sure that students only plot the times that match with velocity values. For instance, no instantaneous velocities can be obtained from the first and last times and therefore those times should not be plotted.
• Also, in the first exercise using a level air track, the velocity curve should be horizontal indicating a=0. However, when students use Excel to plot their data, they may be confused because Excel automatically scales the velocity axis making it look as though the data is randomly displayed. Students should fix this by manually scaling the vertical axis. (For a refresher on this, see the on-line Excel Tutorial on adjusting the graph's scale.)
• In the final exercise, catch the picket fence when it dropped; do not allow it to crash to the table top.
• It is important that the picket fence falls straight through the photogate in the free-fall exercise.

Data, Results and Graphs

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As of now, there are no on-line answers to the questions for this experiment.

Lab Manual

The Lab Manual for this experiment does not exist on-line.

CUPOL Experiments

Take a look at these CUPOL experiments for an on-line laboratory experience:

If you have a question or comment, send an e-mail to Lab Coordiantor: Jerry Hester