# Accounting For Error on Air Track, Conservation Lab

• WoodyHD
In summary, in order to prove that momentum and energy are conserved in this lab, it is important to minimize the effects of non-conservative forces and to use accurate data and calculations.
WoodyHD
This is a conservation of momentum/energy lab. We have an air track with motion sensors at both ends. Bumpers are staged to give elastic collisions. There are two gliders on the track. For this part the second glider remains stationary near the center of the track. The first glider is sent to collide with the second. The motion sensors track their positions and give us the information I provided below. To give us an accurate graph we had to fix much larger flags to the gliders which increase air resistance. From this we have to prove that momentum and energy are conserved.

Now here is the catcher. My professor told us we have to be under 0.1% error.

How I've been calculating this out is by taking the velocity right before the collision and both right after on the graph and using that to find kinetic energy. That by itself on this particular run gives me a little under 3% error. Now because the collision is not instantaneous there is a dt. So I found the work done by air resistance over the uninterrupted part of the graph. Assuming this remained constant through the collision (I'm guessing this is where I'm wrong) I applied that dW/dt to the collision time, meaning I accounted for the work done by air resistance. No mater at what points I find the work or try to manipulate these numbers I cannot get a value below even 1%. Best I can come up with is about 1.3% error.

Now what can I do to account for this error. If there is 3% error I need to account for those nonconservative forces.

Also, this is my first college physics class so I don't have anything to compare to. Doesn't 0.1% error sound kind of extreme?

Glider 1 (blue) 0.2007g
Glider 2 (red) 0.1901g

Initial Velocity of Glider 1: 0.855m/s Final Velocity of Glider 1: 0.288m/s Final Velocity of Glider 2: 0.498m/sThe best way to reduce the error is to minimize the effects of non-conservative forces, such as air resistance. This can be done by reducing the size/weight of the flags attached to the gliders, or by attempting to make the collision instantaneous. It is also important to ensure that the motion sensors are properly calibrated and that the data collected is accurate. Additionally, it may help to try to measure the work done by air resistance on both the gliders before and after the collision, as this can give you a more accurate picture of the energy transfer during the collision. Finally, it may help to use more sophisticated mathematical methods in order to calculate the energy and momentum more accurately.

## 1. What is the purpose of accounting for error in the Air Track Conservation Lab?

The purpose of accounting for error in the Air Track Conservation Lab is to ensure the accuracy and reliability of the experimental results. By identifying and quantifying sources of error, scientists can improve the precision and validity of their data, leading to more meaningful conclusions.

## 2. What types of errors should be considered in the Air Track Conservation Lab?

There are several types of errors that should be considered in the Air Track Conservation Lab, including systematic errors, random errors, and human errors. Systematic errors are consistent and can be identified and corrected, while random errors are unpredictable and can be reduced by taking multiple measurements. Human errors, such as incorrect measurements or data entry, should also be considered and minimized through careful experimental design and data recording.

## 3. How do you calculate and account for error in the Air Track Conservation Lab?

To calculate and account for error in the Air Track Conservation Lab, scientists use statistical tools such as standard deviation and percent error. Standard deviation measures the variability of a set of data points, while percent error compares the measured value to the accepted value. By including these calculations in the experimental analysis, scientists can quantify the amount of error and adjust their results accordingly.

## 4. How does accounting for error impact the overall findings of the Air Track Conservation Lab?

Accounting for error can greatly impact the overall findings of the Air Track Conservation Lab. By identifying and minimizing sources of error, scientists can increase the precision and accuracy of their results, leading to more reliable and meaningful conclusions. Additionally, accounting for error allows for a more thorough understanding of the limitations and potential biases of the experiment.

## 5. Can you provide an example of accounting for error in the Air Track Conservation Lab?

One example of accounting for error in the Air Track Conservation Lab is calculating the percent error for the conservation of momentum. The measured momentum of the system can be compared to the predicted momentum based on the initial conditions, and any differences can be attributed to error. By including this calculation, scientists can account for and minimize the effects of error on the results of the experiment.

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