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Lab 1 - Measurement and Graphing
May. 30th, 2014 06:26 pmMaterials
String
Scissors
Ruler or meter stick
Several round objects of various sizes (soup can, paint can, coins, cups, etc)
Procedure
1. Collect several round or cylindrical objects. These can be any size, so long as you are able to measure the diameter and the circumference.
2. Measure the diameter and the circumference of each object. Record your measurements on the data sheet. You may use inches or centimeters, just be consistent. Measure the circumferences by wrapping a string around the object and then measuring the length of the string.
3. Plot the data points on the axes shown. Scale your axes properly, according to the data. Label your axes with correct units. Plot diameter on the horizontal axis and circumference on the vertical axis. Title the graph “Circumference vs. Diameter” or something similar.
4. Draw in an approximate best fit line. The line should be straight. Use a straightedge. The line does not have to go exactly through the points, but should be as close as possible to all of them while remaining straight.
5. Pick two points on the best fit line, one near each end. These points do not have to be actual data points from your measurement, although they may be if your line actually goes through the points. They should be points on the best fit line, and they should be relatively far apart, one near
one end and one near the other. Call the point on the left P1 and the one on the right P2. From the graph, read the value for the diameter and the circumference for each of these points. Record the values on the data sheet
6. Use the two points to calculate the slope of the line. Remember that slope is always rise/run. In this case, the rise is the change in the circumference from P1 to P2, and the run is the change in the diameter from P1 to P2. Calculate the slope. Show your work and your final answer on the
data sheet.
7. There is a correct answer for the slope, an actual value that you would get if your measurements were perfectly accurate. If you know what this value should be, continue to step 8 and calculate your percent error. If you do not know what the correct value should be, ask your instructor, then continue to step 8.
8. You will now calculate your percent error, which will tell us how far off your value is from the correct value. Percent error is found with the following formula:
%error = |(measure value - actual value) / actual value| x 100%
Note the absolute value signs. The answer will always be a positive number. Calculate your percent error in the space on the data sheet.
9. Make sure your name is on the data sheet and turn it in.
String
Scissors
Ruler or meter stick
Several round objects of various sizes (soup can, paint can, coins, cups, etc)
Procedure
1. Collect several round or cylindrical objects. These can be any size, so long as you are able to measure the diameter and the circumference.
2. Measure the diameter and the circumference of each object. Record your measurements on the data sheet. You may use inches or centimeters, just be consistent. Measure the circumferences by wrapping a string around the object and then measuring the length of the string.
3. Plot the data points on the axes shown. Scale your axes properly, according to the data. Label your axes with correct units. Plot diameter on the horizontal axis and circumference on the vertical axis. Title the graph “Circumference vs. Diameter” or something similar.
4. Draw in an approximate best fit line. The line should be straight. Use a straightedge. The line does not have to go exactly through the points, but should be as close as possible to all of them while remaining straight.
5. Pick two points on the best fit line, one near each end. These points do not have to be actual data points from your measurement, although they may be if your line actually goes through the points. They should be points on the best fit line, and they should be relatively far apart, one near
one end and one near the other. Call the point on the left P1 and the one on the right P2. From the graph, read the value for the diameter and the circumference for each of these points. Record the values on the data sheet
6. Use the two points to calculate the slope of the line. Remember that slope is always rise/run. In this case, the rise is the change in the circumference from P1 to P2, and the run is the change in the diameter from P1 to P2. Calculate the slope. Show your work and your final answer on the
data sheet.
7. There is a correct answer for the slope, an actual value that you would get if your measurements were perfectly accurate. If you know what this value should be, continue to step 8 and calculate your percent error. If you do not know what the correct value should be, ask your instructor, then continue to step 8.
8. You will now calculate your percent error, which will tell us how far off your value is from the correct value. Percent error is found with the following formula:
%error = |(measure value - actual value) / actual value| x 100%
Note the absolute value signs. The answer will always be a positive number. Calculate your percent error in the space on the data sheet.
9. Make sure your name is on the data sheet and turn it in.
