### Energy, Entropy, and Everything

Honors 1500, Perspectives in the Physical Sciences

## First Project Assignment (due Friday, February 2, 4:00 p.m.)

In class on Thursday, January 18, we did a simple experiment: shaking a small bottle of water to convert mechanical energy into thermal energy. Simple though it was, this experiment was essentially the same as James Joule's famous paddle-wheel experiment, which was the first careful measurement of the "mechanical equivalent of heat".

Your assignment for this Project is to write up the results of your experiment, as if for publication in a modern scientific journal.

First, make sure you have decent results to write up. Repeat the experiment if necessary, carefully measuring the change in temperature as you shake a small amount of water for a few minutes. Estimate the total number of shakes, and the amount of kinetic energy given to the water during each shake. Use your data to calculate the "specific heat capacity" of water, both in joules per gram per degree and in calories per gram per degree. Check that your result isn't too different from the accepted, textbook value.

Now you're ready to start writing. The format of a scientific journal article is fairly standard and rigid, so you don't need to make any major decisions in organizing the paper. Basically, the paper should have three parts: an introduction, a description of what you did, and a summary of your results.

The purpose of the introduction is to grab the reader's attention. Briefly describe what you tried to measure (just what--not how) and why it's interesting. Feel free to provide some historical context (perhaps the earlier experiments of Rumford and Joule). For this short paper, the introduction should be only about half a page long.

The details of what you did belong in the description section. Here you should carefully describe your experiment, in enough detail so that any intelligent reader could repeat it. State the results of your basic measurements (initial and final temperatures, how long you shook the bottle, how many shakes per second, distance of each shake, etc.), and then explain how to calculate (roughly) the specific heat capacity from this raw data. The length of this section should be at least a full page.

The last section should state your results and conclusions. State your calculated value for the specific heat capacity of water. Discuss some reasons why this value is somewhat uncertain. Compare your value to the accepted textbook value, and discuss whether the two values are consistent with each other (given the uncertainties). Describe how you could improve the experiment to reduce the sources of uncertainty. The length of this section should also be at least a full page.

After you've written all three sections, you should also write an abstract. The purpose of the abstract is to summarize the entire paper, including the final, numerical result, in only three or four sentences (for the benefit of those who are too busy or too lazy to read the whole paper). Although you should always write the abstract last, it conventionally goes at the beginning of the paper, set off typographically by using narrower margins or single spacing or some similar device.

The total length of your paper, including the abstract, should be three to four pages, double spaced (assuming a normal font size and margin width). Don't bother to add a cover page or clear plastic binder or anything.

General advice on writing: Use your best spelling, grammar, and paragraph structure. If you think you might need help with these basic writing elements, feel free to consult with me or with the staff of the Writing Center (Student Services building, room 261). Even though this is a scientific paper, the tone should be relaxed and not too formal. Write in the first person ("I shook the bottle"), not in the passive voice ("The bottle was shaken"). Remember that the main goal is to communicate clearly, so that a reader can learn what you did without undue effort. Try to forget that your actual reader will be a professor who already knows what you did!

If you have any questions about this assignment, please ask.

Last modified on 17 January 2001.