Pendulum Data:

Use the data in this table to create two graphs: L vs. T, and L vs. T2. For L vs. T, on the x-axis one interval equals 5 cm. On the y-axis, one interval equals 0.1 second. For L vs. T2, on the x-axis one interval equals 5 cm. On the y-axis, three intervals equals 1 second. Use pages 46 and 47 in your lab manual. For L vs. T2, use a straightedge to draw the "line of best fit".

Group Project Brainstorming Continues

The brainstorming process is a continual one. Remember to log-on to Google Docs and add some more ideas to your list. You can also take one of your general topics and try to make it more specific. Ask a more specific question or propose a hypothesis for a question asked by a team member. Some groups have already started writing proposed procedures for some of their SOPs. This is also a good idea. Keep the ideas coming!

Summary of Delta Mass Experiments:

In each of the experiments we did involving a question that began with the words: "Does mass change when. . .?", we found that mass did not change. In each experiment (ice & water, dissolving salt, and copper & sulfur) some type of a change took place. We made sure that the change took place within a closed container. This was important because we were trying to find out if the change in matter caused the difference in mass--we wanted to make sure that evaporation and spillage were not the reason for any measured change in mass.

Because we are not perfect, and our balances are not perfect, and mistakes are inevitable, we tried to collect as much data as possible so that we could minimize the effects of those imperfections on our results. Even though some groups' measurements would indicate that mass either increased or decreased, there were many more groups that found that there was no change in mass. We used histograms to help find the pattern in the data--and in every experiment the vast majority of data "stacked up" around the zero on the x-axis, indicating that the mass did not change.

In all of this, remember that our EABs are only reliable to (approximately) +/- 0.05 grams. Any time our measurements changed within that range we still considered that test to show "no change in mass".

Experiments like these 3 helped scientists establish a very important law of nature--the "Law of Conservation of Mass". This law states: In all changes, mass is exactly conserved. Please know this law for the next quiz and be able to offer some experimental evidence that supports it.

If you have any questions about this summary, please ask before the next quiz (which will be late next week).

Problems to Avoid. . .

Time Table for GROUP PROJECTS

Last week's poll is closed. . .

Try to visit every night!

New Video Bar Feature!!!! SCIENCE PROJECT IDEAS

Be sure to check out the Video Bar feature at the bottom of the page--there are some good project ideas to get you thinking about your own project. You could get extra points on a quiz if you watch these videos and pay attention!

Section 7H-ORANGE

Since we "forgot" the quiz on Friday, we will have a quiz on Monday. Naturally, since you had an extra week-end to study, your quiz will be a bit longer and more thorough than the quiz scheduled for Friday. Know your histograms! Be sure to check out the study tips on the Thayer website.

Histogram for Copper & Sulfur Experiment

You can use this histogram in the Data section of your Lab Report (so you don't have to make a new histogram from scratch).

Possible Diagrams for Lab Reprot #2

You can use the "command, shift, 4" short cut to include these diagrams in your report. Don't forget to label them.

This week's QUIZ:

Be sure you know your histograms. Know how to enter data into a histogram. Know how to determine the value of an interval on the x-axis. Know what to do when a data point lands directly on a boundary between two intervals. Know how to define a boundary and an interval. For practice, make a histogram using the data from the "Dissolved Salt" experiment. (Use an interval size of 2 one-hundredths of a gram, and put zero at the center of an interval.) Know what the label is on the y-axis of a histogram. Know what the "gray area" on the x-axis represent on the "Mass of Ice & Water" histogram. Ask questions in class if you are confused. . .(be smart and ask your questions BEFORE the quiz).

Mass of Dissolved Salt Data

Due 12/12/2008:

Lab Report #2: Using the lab report template (provided last term and available in Mr. Hamilton's public folder) and the Lab Report Rubric, prepare a lab report addressing any of the Delta Mass experiments (Ice & Water, Dissolved Salt, Copper & Sulfur) that you have completed in the lab. Data tables and histograms should be available on this site and in the DOWNLOADS section of the Thayer site.

HISTOGRAM: Mass of Ice to Water