Ani,+Ariel,+Sammy,+Rachel+Chapter+6

=Lab 1: Spring Constant=

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 * Group Members:** Ani Papazian, Rachel Caspert, Sammy Wolfin, Ariel Katz
 * Class:** Period 2
 * Date Completed:** March 7, 2011
 * Date Due:** March 8, 2011


 * Purpose:** **The purpose was to find the spring force constant of the given spring.**


 * Hypothesis:** **If different masses are added to the spring, then by collecting the data and noticing the change in position, we will be able to find the spring force constant**


 * Materials:**

**Spring, stand, multiple hanging masses (10g each)**

**Procedure** **1. Set up spring on the stand with a mass hanger** **2. Add masses one at at time and record the change in where the spring now hangs down (where the spring started is 0)** **3. Continue to add masses and record, all recordings are based on the original position of "0"** **4. Create graph on excel that shows force vs. change in distance** **5. After finding the slope of the line, you can assume this is the spring force constant.**


 * Data:**



slope = 3.7054 = k value (N/m)





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 * Calculations used for theoretical velocity:**

Class Results:
 * Percent Difference for K:**



when x = .2 m, the percent error is .18% When x = .3 m, the percent error is 2.32%.
 * Percent Error for trials:**



When x = .4 m, the percent error is 3.5%. When x = .5 m, the percent error is 2.7% When x = .6 m, the percent error is1.7% average percent error = 2.075%

1) Does K value agree with class? Should it? The K value agrees with the class. There is a very small percent difference between our K value and the class's K value. The calculations above show that the percent difference is only .067%. Since the springs were essentially the same, the K value, or spring constant, should have been the very close to the same.
 * Discussion:**

2) V vs. X relationship. Discuss fit. There is a direct linear relationship between velocity and change in distance. In the equation, the K-value and mass are both constant. Then the velocity squared and distance squared can simplify to just velocity and distance (therefore no longer a square relationship). So as we increase the change in distance of the spring, the velocity of the spring increases.

After completing this experiment, we proved our hypothesis to be true. Through our lab we saw that the farther the spring was pulled back, the faster the cart velocity was as it passed through the photo gate. Since our K value had a percent error of less than 1%, our experiment was pretty accurate. This slight error could have been caused by the friction between the cart wheels and the track that we ignored but was actually present.
 * Conclusion + Error Analysis:**