Purpose The purpose of this lab is to use linear regression and data analysis to calculate the elasticity constant for a single spring, and for springs arranged in series and in parallel. Equipment
- two springs
- slotted masses
- mass hanger
- trapeze
- LabPro
- meter stick/ruler (optional)
Procedure and Data Tables
Part I: Single springs. Complete ten trials for each spring. Before suspending each spring measure its equilibrium length.
Suspend the spring with its empty mass hanger from the trapeze and align the distance detector directly underneath. Run LoggerPro (Start, Programs, Math, LoggerPro 3.1) and use the data table on the left side to approximate, to three decimal places, how far the bottom of the mass hanger is suspended above the motion detector. Record this answer in your data table. Then increase the hanging mass by increments of 100 grams and record each subsequent stretched position.
Continue until you have suspended a total of 950 grams from each spring. Please note that the empty mass hanger has a mass of 50 grams. Complete the following data table for each individual spring.
At no time during each phase of this experiment are you allowed to change the height of the suspension point on the trapeze. If the bottom of your mass hanger comes closer than 40 cm above the motion detector, it will no longer provide correct readings.
single spring #1
|
Equilibrium position
|
_____________
|
Trial
|
Total Hanging Mass
|
Total force (mg)
|
Stretched position
|
1
|
50 g
|
|
|
2
|
150 g
|
|
|
3
|
250 g
|
|
|
4
|
350 g
|
|
|
5
|
450 g
|
|
|
6
|
550 g
|
|
|
7
|
650 g
|
|
|
8
|
750 g
|
|
|
9
|
850 g
|
|
|
10
|
950 g
|
|
|
single spring #2
|
Equilibrium position
|
_____________
|
Trial
|
Total Hanging Mass
|
Total force (mg)
|
Stretched position
|
1
|
50 g
|
|
|
2
|
150 g
|
|
|
3
|
250 g
|
|
|
4
|
350 g
|
|
|
5
|
450 g
|
|
|
6
|
550 g
|
|
|
7
|
650 g
|
|
|
8
|
750 g
|
|
|
9
|
850 g
|
|
|
10
|
950 g
|
|
|
Part II: Springs in Series. Complete five trials using both springs arranged in series by linking them together one below the other. Initially record the equilibrium length of the springs without any suspended masses. Complete five trials ranging from 50 grams to 450 grams.
springs in series
|
Equilibrium position
|
_____________
|
Trial
|
Total Hanging Mass
|
Total force (mg)
|
Stretched position
|
1
|
50 g
|
|
|
2
|
150 g
|
|
|
3
|
250 g
|
|
|
4
|
350 g
|
|
|
5
|
450 g
|
|
|
Part III: Springs in Parallel. Complete five trials using both springs arranged side-by-side, or in parallel. Initially record the equilibrium length of the springs without any suspended masses. Complete five trials ranging from 150 grams to 950 grams. Be careful to make sure that the suspended masses are centered so that they are supported equally by both springs.
springs in parallel
|
Equilibrium position
|
_____________
|
Trial
|
Total Hanging Mass
|
Total force (mg)
|
Stretched position
|
1
|
150 g
|
|
|
2
|
350 g
|
|
|
3
|
550 g
|
|
|
4
|
750 g
|
|
|
5
|
950 g
|
|
|
Data Analysis EXCEL will now graph your data. Minimize your browser, double click My Computer, double click the shared drive called colwell/bay on Lederman, double click your period's folder and then finally double click 1- HookesLawLabPro.xls. You will most likely be asked to open the file as "read only" - that is fine. As soon as the file is open, use File Save As to rename the file as
LastnameLastnameHookesLawLabPro.xls
in your period's folder. This copy of the file now belongs uniquely to your group. Remember that there are to be no spaces in the file name. |