Pfautz+Lab+10


 * Lab 10: Atwood's Machine**


 * Purpose:** The purpose of this lab was to learn how to use and make calculations with an Atwood's machine as well as examine the relationship between mass and acceleration.


 * Hypothesis:** It is hypothesized that the greater the difference of mass of the two cups, the greater the acceleration. Also, the smaller the difference of mass of the cups, the less acceleration and when the cups are equal in mass there will be no acceleration. It is also hypothesized that when the masses of each cup is increased equally, the acceleration will remain generally the same.


 * Apparatus:**
 * Computer
 * Vernier computer interface
 * Logger Pro
 * Vernier Photogate with Ultra Pulley
 * Mass set
 * String

Part I Part II 9. Put 120g in cup 1 and 100g in cup 2 10. Repeat steps 6 and 7 and determine acceleration 11. Add mass in 20g increments to each side and repeat steps 6 and 7 for each combination
 * Procedure:**
 * 1) Set up Atwood's machine apparatus so that the heavier mass can move at least 40cm before touching the ground
 * 2) Connect the Photogate with super pulley to DIG/SONIC 1 of interface
 * 3) Open the graph of velocity vs. time
 * 4) Set up the pulley so that there is 200g in each cup. Record the acceleration and mass
 * 5) Move 5g from cup 2 to the other and record
 * 6) Move the heavier cup 2 up as high as it can go, let go and record the acceleration
 * 7) Examine the graph in the region where velocity was increasing at a steady rate. Use the linear fit button to find the slope which is the acceleration
 * 8) Continue moving masses in 5g increments from cup 2 to cup and repeat steps 6 and 7 for each mass combination


 * Data:**




 * Analysis:**

(GRAPH HERE)

This graph shows that the change in mass and acceleration are directly proportional to each other. They both are increasing. This can be represented with a strong positive linear model.

(GRAPH HERE)

The total mass and acceleration are inversely proportional to each other if the change in mass is constant. There is a clear negative correlation.

The hypothesis that the greater the difference of mass of the two cups, the greater acceleration, proved to be true. It was supported by the linear correlation of the Change in Mass vs. Acceleration graph which showed a direct relationship between the acceleration and the change in mass. The hypothesis that the smaller the difference, the less acceleration also was supported by the total mass vs. acceleration graph. Lastly, the prediction that no acceleration would occur when the masses were equal was also correct. The cups showed no motion when they were of equal mass. In order to improve this lab, more trials should be run so that more data would be available and results could me more accurate. It would also be helpful if more masses were available so that odd objects that had tendencies to fall out of the cups would not have to be used. This skewed some of the data and caused problems throughout the experiments.
 * Conclusion:**