Details for the Galileo Lab Report

Note, if you are using a Mac, you might want to send me a PDF instead of a MS Word File, so the graphics are properly embedded.

You should have read the general guidelines for the lab report on this conference.  Some details to consider.   This is the bare minimum of what you should include.  This will be briefer than a normal lab report because the theory is pretty simple.


Summarize the entire lab in 3-5 sentences. Mention what happened.  Mention what result you got for acceleration and any percent errors.   It is common to write the abstract last, after you have said all you want to in the rest of the lab report.


Explain the following concepts: Acceleration, velocity, gravity.
Explain/derive the following equations:

D = ½   gt2 look in the endnote on p 43 of your text
Add any interesting historical connections to the theories/this experiment (hint Galileo)
Explain, using the theory of inertia and Newton’s 2nd Law and the formula for weight why the acceleration is the same for all objects.
Although not required for the rough draft, you could go so far as to show where the number 9.8 comes from.  But this should be included in the final draft.  This uses Newton’s Universal Law of Gravitation which is in the readings.   Using the primary sources, you will probably have citations and will need to use footnotes OR parenthetical citation.


Include diagrams/sketches/pictures. They may be hand drawn and scanned in, or you may use digital photographs of the equipment, or drawn with software such as COREL Draw.  Make sure you give photo-credits if you did not take the pictures.
Mention all the equipment (do not list the equipment).  Describe what happened, the total procedure.  Use 1st person plural past tense.  Note, graphing the data is not considered part of your procedure, this is analysis.

Results and analysis

Present your data.  Present your graphs, which should have the equation of the line on it.
Explain the connection between the equation on your graph, and what theory predicted.
So what is the actual acceleration of your object?
Calculate percent error.  Explain the reasons for any errors.  Don’t say “human error.”

You should be comparing your results to that of your peers.

If you use peer data, make sure you explain this.  You may need to retype peer data so it is presentable.


Summarize everything.  Include proposals for future experiments.  How could the experiment be improved if you had more time and funding? Different ways to measure. Other instruments?  In what ways could you have eliminated the sources of error you listed in the Results and Analysis section?


You need to have a bibliography.  You must use one primary source.  I will try to put some sources on reserve in Mugar.  You will probably use your textbooks, which are secondary sources.  Asimov’s Understanding Physics would also count as a secondary source.   You can include sketches, tables and graphs here, if you chose not to insert them into the middle of your paper.


Primary Sources:

For this first lab report, make sure you read
Hewitt Conceptual Physics which is a SECONDARY SOURCE
P 43  Derivation of Law of Falling Bodies in the 11th edition (12th ed  p 48)
P57  Explanation of acceleration and g (12 ed p 64)

You can find great primary sources on Google Books, and in Mugar.  In the Physics Great Hall Books folder are several texts in the History of Physics folder.

If you find any extra sources, please feel free to post to the Physics Great Hall.


If you want to directly quote Aristotle on his observations of falling objects, or his natural elements theory, then it is in his book, Physics, or Physica.  The particular section is Book IV, Part 8.


There is a digital copy of Newton’s Principia, some works by Aristotle, and Galileo’s Dialogues of Two New Sciences.   Also a very interesting article on Galileo from the American Journal of Physics.

Some suggested readings:
From the Principia
All page numbers given in the PDF page #
The 3 Laws: PDF p 89
Law of Gravitation p224
3rd Law and attraction p 98


De Motu (by Galileo) is an interesting text because it was written early Galileo’s life, and thus much of it is actually wrong.

Galileo’s Dialogues Concerning Two New Sciences
The introduction of the text has a nice historical time line of Galileo’s work in the early 1600’s
His discussion of falling objects was on the 3rd and 4th day.
I give you page numbers from the Italian version, which you will have to scan the English version to find these (don’t use the Italian page numbers in your citation)
p 197  Natually Accelerated Motion
p 205 Postulate on speed vs height
p 209-210 Law of Falling Bodies – uses geometry not algebra
p213 Inclined Plane experiment
p 274  Idea of parabolic path of projectiles (inertia)
p275  Air resistance
p 276-7 Concept of Uniform Acceleration
p286  Acceleration g is the same everywhere on Eath

Recent Article from American Journal of Physics

There is also an AJP article on a correction to Galileo’s free fall law.  Don’t read past the second page.  It gets confusing.  Advanced stuff.