Monday, November 17, 2014

Wednesday, November 5, 2014

Earth science Mass lab guide sheet

Do not write on this handout, make an RD in your notebook, the FD will be on a separate sheet(s) of paper one for each student.

Title:  Just how much Rubber is in a Rubber Stopper?
Question:  How will the rubber stopper’s actual metric mass compare (more, less or same mass) to the converted mass taken from posted English standard measurements?

Hypothesis:  The Rubber stopper’s actual mass will be________________ then/as the posted mass.

Test:  By using a metric balance to determine the actual mass of a Rubber stopper, we can convert ounces to grams for the posted mass and compare to the actual mass found using a scale.

Materials:  metric balance (triple beam pan balance), rubber stoppers of varying size, (calculator)

  1. Convert the posted mass from oz → g using the following formula 1oz. = 28.3 g 
  2. Take the mass measurement of the rubber stopper on the metric balance.  Each group member should separately find the mass using the metric balance.  Zero scale between trials and find the average for the object and enter into the data sheet.
  3. Do this for four different rubber stoppers with different posted masses (each table member should do all parts of the experiment for at least one sinker)
  4. Subtract the measured mass in grams from the posted mass in grams to determine the relative error.  You may disregard any negative numbers9 take an absolute value of your result).
  5. Take the relative error in grams and divide by the converted posted mass, in grams, and multiply by 100 to determine the percent error.

Rubber stopper #
Posted mass
Converted (g)
Average measured mass
Relative Error
% error


Analysis:  include your calculations and math work for doing the oz-g conversions, relative and percent error. 
Make a Bar graph of actual versus converted mass values of the rubber stoppers used.

Conclusion: (restate the hypothesis, explain how you answered the question or not and compare numeric results to prove or refute your hypothesis, discuss observations as possible errors and propose a next step and who outside of this science class might care about your results)