Stacey+and+Jen+Clock+Lab

=​Clock Design: Simple Harmonic Motion= Date of Publication (Date of Most Recent Edits)

**Participants**: Jen Grobe and Stacey Schellong
 * Purpose** : The purpose of this lab is to design and characterize a clock that is makes accurate time measurements in the range of 30 to 90s.
 * Lab Documents**: [[file:Simple Harmonic Motion.doc]]

**Brief Description Clock Design **: Our clock is a pendulum. The string length was 67cm. We used a 1000g weight at the bottom of the string. Our release point was 180 degrees, parallel with the metal bar (85cm). media type="file" key="Block 2; Pendulum 3.wmv" align="center" width="275" height="242"
 * Specifications of Clock: ** In 30 seconds our pendulum swung 30 times. In 60 seconds our pendulum swung 64 times.

** Design Variables: ** The length of the string is one of the variables that had the greatest influence on the number of swings. The mass also influenced the number of swings but was not as great of a factor. Also the release point had a large impact on the number of swings.
 * Studied Design Variable : ** The first variable we chose was the mass. We used six different weights and counted the number of swings that occurred in 20 seconds. We found that the swings got closer to one swing per second as the mass increased.


 * Studied Design Variable 2:** The second variable we tested was the length of the string. We used a weight of 200g and measured the number of swings in 20 seconds for four different string lengths. We found that the number of swings became closer to one swing per second as the sting got longer.

**Lab Questions**: Write out and answer any questions that are included as a part of the lab.
 * 1) Our pendulum swung at approximatly 1 swing per second, so you could time something that lasts 60 seconds by counting out 60 pendulum swings. Our accuracy is within 10 percent: we counted 64 swings in 60 seconds.
 * 2) The length of the string was the variable with the greatest impact. ​ Based on our graph above of this variable, by making the string increase from 34 cm to 41 (about a 20% increase) the number of swings in twenty seconds went from 28 to 26. So the longer the string, the closer to one swing per second.
 * 3) The mass of the weight at the bottom of the string had the least impact. Based on our graph we can predict that if the mass were to increase to 1200 grams, it would have very little or no affect on the number of swings per second.
 * 4) Our pendulum clock would not be successful at measuring a time from 10 to 15 minutes because as it approaches the 60 second mark it is already beginning to swing faster than one swing per second. This is because the longer the pendulum swings, the momentum declines and it loses distance.

**Conclusion**: A good conclusion will include:
 * We have learned about the strong impact the length of the string has on the pendulum and the little impact the mass has, so we could definitly reproduce our clock.
 * <span style="color: #0000ff; font-family: Georgia,serif;">As the momentum of the swing decreases, the distance travelled decreases, and the speed of the pendulum will increase. So, even if our clock begins swinging at one swing per second, it will eventually speed up faster than that.

> > //Don't forget to link to your lab report from the lab reports page and to include a link to your lab report in your reflection.//
 * Independent reflection:** One lab report will be turned in for each group. In addition, each student must complete //independently// a reflection addressing the following questions:
 * How was the process of designing and testing a clock similar to the scientific method as discussed in class?
 * How did it differ?
 * What "steps" in the scientific process were present and which were missing?
 * Was there a part of the activity that is not a part of the scientfic process?