Class 12

PARENTS & STUDENTS (Tue 8:10pm):  Wouldn't it be fun and look nice if the students decorated the room of the Science Fair (whose theme is GRAVITY) with color or black-and-white artwork, cartoons, even poems or famous quotes ABOUT GRAVITY!! 

-- We'd need a size limitation -- How about two standard (8 1/2 x 11 inch) sheets of paper taped together in any orientation you like.

-- We'd also need a maximum number of entries per student -- How about two.

There will be a prize for the winning art entry and "Certificates of Achievement in Gravitational Art" for all entries.  MAKE SURE TO WRITE YOUR NAME ON YOUR ENTRY (or ENTRIES).

There will also be three prizes for the top three Science Fair projects and "Certificates of Achievement in Gravitational Science" for all entries.

Please use your own imagination, but here are a few ideas just to get you thinking:

ART:   Modern art color drawing of planets swirling through the Universe.

CARTOON:  People tumbling off the Earth and yelling things like "HELP!! We lost our gravity!" 

CARTOON:  Galileo Galilei dropping a big stone and a small stone off the Leaning Tower of Pisa and yelling to his wife down below:" Maria!  Which one is going to hit first??"

POEM:  Oh Gravity, dear Gravity,
               I lost my natural suavity,
               And took on base depravity,
               When you pulled the filling
                           from my cavity!
(NOTE - not many words end with "avity", but lots end with "ivity" and still rhyme with gravity.)

QUOTE:     “There is no need to use force. Instead, create a path of least resistance, and gravity will do the rest.” 
                                      ― Michael Dunlap

PARENTS (Tue 2:00pm :  I would like to have all students from each family - one family at a time - over to our apartment for several hours (on Sunday morning or afternoon, if possible).  This is so I can help them make their Science Fair Apparatus (I will have all the materials and tools) and coach them on what they are supposed to do .  For families of one student, 1 1/2 hours will suffice; for 2 students, 2 1/2 hours; for 3 students, 3 hours.  Please email, text or phone me to set up the meeting.

PLEASE NOTE -- A parent will need to be present at all times with the student(s).

Date                                                Students
Mar 23, 3:00-5:30pm                    SAV.,  ELI.
Mar 30, 10:00-11:30am                LAY., Aft  OPEN
Apr 06                                             NOT AVAIL.
Apr 13                                             Morn OPEN; Aft OPEN
Apr 20                                             Morn OPEN; Aft OPEN

If special arrangements are better, please let me know.

(Special arrangements:)

Mar 26, 2:00-5:00                          JON., KAI., ASH.
Mar 31, 3:45-5:15                          SAM.
Apr 01,  4:00-5:30                          TRI.

Thank you!


STUDENTS (Mon 7:30pm):  Here is what you need to finish and bring to class on Thursday:

1.  Your Science Fair (Science Project) Proposal:  Let me repeat how you do it:  HERE IS AN EXACT EXAMPLE, using Kai's Project:  You do the stuff in blue, you copy and paste the stuff in green straight from the Class 11 BLOG.

                             Science Fair Project for YHB Physical Science Class

TYPE "TITLE" then TYPE the NAME OF PROJECT, and so on.  

TITLE:                   COMPARE THE PERIODS OF A PLANAR PENDULUM AND A CONICAL ONE.

AUTHOR:              Kai W. C****

ASSISTED BY:      Adr C****, Ash W. C****, Jon W. C****, F. A. D******* <-- Kai, do this as you wish.

PURPOSE:   To compare the periods of a planar and a conical pendulum  relative to changes in (1) mass, (2) length and (3) angle.  They look similar, but the way the gravitational forces act in the two systems is completely different , and it is difficult to guess how they will behave versus the independent parameters of mass, length and angle.

BACKGROUND:  (Lots of Googling here.) (from wikipedia.org -- I searched on "pendulum")  The pendulum was first investigated around 1602 by Galileo Galilei. The regular motion of pendulums was the world's most accurate timekeeping technology until the 1930s <-- Kai if you want to say this part yourself differently, that is fine.

METHODS/MATERIALS:  [You’ll need an adult’s help building this.]  (These are just suggestions: there are many ways to build this.)  I will begin by studying the best and most rigid attachment point.  One way is to clamp a three-foot long 2 by 4 onto a worktable (if I use a good table, with my parent’s permission, I will lay a soft cloth on the table under the board before clamping to avoid scratching the table. (Then I can also clamp the board to the display table at B’rit for the Science Fair demo).  I can drill a very narrow hole at the end of the board for the string to go through  (I’ll use something that doesn’t stretch or tangle up when it’s loose -- sewing thread is terrible).  Then I can hammer in two nails into the wood and get five pendulum  lengths ( nail A is, say, 20 cm (8”) from the hole, and nail B is 40 cm from the hole.  First, I make a tight, non-slip loop in the string.  Then I can put the loop on  nail A and tie the sinker so its center is, say, 100cm  below the board.  If I move the loop to nail B, it is 80 cm; and if I loop around B and back to A, it is 60 cm, another loop to B is 40cm, and final loop back to A  is 20 cm.  This is a simple and repeatable method as long as my loop knot doesn’t slip (I could put a glob of strong glue or epoxy on the know to prevent slippage.)  I use or make a clip that snaps open and closed for quick changing of the sinkers to get different weights.  My first try of the parameters will be:

SINKER WEIGHTS (oz*)                 PENDULUM LENGTHS    (cm)        ANGLES (deg)     *convert to grams please!

1                                                              100                                                         10

2                                                              80                                                           20

4                                                              60                                                           40

                                                                40                                                           80

                                                                20

To study                                Number of experiments (10 swings / experiment)

Mass effect                           4 repeats x 3 masses x 1 length (80 ?) x 1 angle (40 ?) x 2 modes (planar and cone) =  24

Length effect                        3 repeats x 4 lengths (drop 80?)  x 1 mass ( 2 ?) x 1 angle (40 ?) x 2 modes =  24

Angle effect                          3 repeats x 4 angles x 1 mass ( 2 ?) x 1 length (80 ?) x 2 modes =  24

I have 72 experiments (of 10 swings each) to do in 2 months.  Each one will take less than a minute, so I can easily do 10-20 experiments a day.  I should be able to do all 72 experiments in less than a week.

I will plot my data on three graphs.  The x-axis will be mass, length and angle.  Each graph will have two curves: one for the planar pendulum and one for the conical one.  For each point (which will be the mean of 3 or 4 repeats) I will show 1 or 2 SDM error bars.    I will require one online computer (for calculations, Google searching, word processing, Excel, etc.)  and a printer to print the results of the experiments and calculation, and create our poster display.

RESULTS:

·                     A poster display summarizing my research

·                     3 plots on the poster showing the results of my period measurements for the planar and conical pendulums

·                     Another plot showing measured speed and theoretical speed versus starting bob height.

·                     Exhibit and demonstrations of my experimental planar and conical pendulum for the judges and attendees.

THAT'S IT, YOUR PROPOSAL IS DONE FOR NOW!

2. Homework 7, if you have not turned it in yet.

3. Homework 8, if you have not turned it in yet.