Steph&Caitlyn's+Clock+Lab

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


 * Participants**: Caitlyn and Stephany
 * 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 90 seconds.
 * Lab Documents**: [[file:Simple Harmonic Motion.doc]]

The spring was attached to a bar by short string. It was tied so that the spring was tight against the bar. There was 750 grams attached to the bottom of the spring. That was what determined the accuracy of the clock. We started with the spring completely coiled. When we let go, the number of times the bob bounced was equivalent to the number of seconds that it had been going for. media type="file" key="Block 2; Spring Clock 1.wmv" width="300" height="300"
 * Brief Description Clock Design**:
 * Specifications of Clock:**

Provide data that describe the accuracy of the clock for measureing times between 30 and 90s. A graph may be useful. Be sure to describe how the tests were performed (procedure). speed = distance / time || There were a few variables that we thought may have changed how our clock operated. The length of the string attaching the spring to the pole, and the amount of weight we had on the opposite end of the spring were both things we considered. Other variables could have been the length of the spring, where we released the spring to let it start bobbing, and what would happen if we changed the length of the string attached to the spring and pole.
 * Sample Calculations:** Describe or reproduce any calculations that are performed during the experiment (other than averaging). For example, if you use a distance and a time to calculate a speed, you should show:
 * //Speed calculation// || The speed in meters per second was calculated by taking the measured distance in meters and dividing by the time elapsed in seconds.
 * Design Variables:**

**Studied Design Variable 1:** When the short spring attached tightly to the pole was used, we found that 750g of weight on the other end of the spring would make our clock accurate. We also found that it didn’t matter where we released the spring; the clock worked the same either way. When we changed the length of the string attaching the spring to the pole, the clock was still accurate.

The second variable we focused on was the length of the spring. The longer spring had a tighter coil than the shorter spring, and we found that in order to be accurate, it took 3000g on the opposite end of the spring. This shows that the tighter the coil the spring has, the more weight it takes on the end to be accurate.
 * Studied Design Variable 2:**

1. Describe in detail how your device may be used to measure an event that lasts 60s. What would the accuracy of this measurement be?
 * Lab Questions**: Write out and answer any questions that are included as a part of the lab.

The spring and mass device was made with a remotely short, loosely coiled spring. We established that in order to be completely accurate, or only off by a fraction of a second, 750g would have to be the weight of the bob. To measure an event 60 seconds long all you have to do is count 60 bounces. This measurement would be pretty accurate only a fraction of a second off.

2. Which variable that you studied had the most significant effect on the frequency/period of the clock? If you built your clock with a 20% increase in this variable, what would the new frequency/period of the clock be? Support your answer by referring to data in your report.

The variable that seemed to have the most significant effect was the weight of the bob. With our data we founded it showed that the heavier the weight the fewer bounces there were. The less weight the faster the springs bounced. Therefore if the mass was increase by 20% slower it would bounce.

3. Which variable that you studied had the least significant effect on the frequency/period of the clock? If you built your clock with a 20% increase in this variable, what would the new frequency/period of the clock be? Support your answer by referring to data in your report.

The variable that had effected the frequency was where we let go of the spring and bob. If we let go of the spring 20 inches from were it started I think that it would start out a little fast but after a short time it would slow back down and bounce at one bounce per second.

4. Though it was not a project requirement, it would be nice if your clock could also measure much longer times, on the order of 10 to 15 minutes. Would your clock design still be accurate for long time measurements? What might affect the accuracy of the clock for these longer measurements? Can you think of a way to improve the design to make the clock more accurate for longer measurements?

A possible thing to try would be to start the clock so that it isn't accurate. It seems as though if it was started with more weight, it would bounce faster, but by the time the 10 to 15 minutes was up, it would be bouncing slower, and there is a chance that it might have slowed down to the point where it could give accurate times.


 * Conclusion**: A good conclusion will include:

This experiment did, in fact, produce valid results, because we were only having it run for short amounts of time. Because of the short amounts of time, the spring wasn't going long enough to slow down and produce invalid results. This experiment showed that heavier weights on the spring caused it to bounce slower, and lighter weights made it bounce faster. We knew that the weight would have to be more than 500g but we were not sure how much more it would have to be so we tested different weights. We did not have difficulties doing this experiment and I’m not sure why that is it just seemed like common sense to me. If one weight is too much take away weight, if there is not enough weight we just add more.

> > //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?