Physics AP - Pith Ball Lab (#15)

Background:
When Mr. Franklin chose the charges that move he chose negative.  But
when he chose negative all the answers became negative.  So in
physics we pretend positive charges move.  Two negative charged
things repeal each other as two positive charges repeal each other.
Positive charges hate each other so much that they are whiling to go
through humans to get a way from other positive charges.  They will
only go as apart until the elbow from in each space is all the same.

Problem:
To find weight, tension in the string, force or electrons (Fe) and
charge (q).

Procedure:
1. First rub the rabbit fur on a vinyl strip to put on the positive
   charges.
2. Draw force body diagram, put the vinyl strip next to the two pith
   balls, so that the pith balls are positively charged.
3. Measure the distance between the pith ball, and the length of the
   string.
4. Find the weight by using w=mg.
5. Find the tension by using TcosØ=mg.
6. Find the Fe, Fe=TsinØ.
7. Find q by Fe=(kq1q2)/r².

Data:
       TcosØ
        /|\  T
         |  /
         | /
   Fe<---O--->TsinØ
         |
        \|/
         mg

Weight
W=mg
W=8.7×10^-5
W=(8.53×10^-4)N

Tension          Fe                      Charge (q)
TcosØ=mg         Fe=TsinØ                Fe=(kq1q2)/r²
TcosØ            Fe=8.57×10^-4×sin(5.5)  8.21×10^-5=(9×10^9×q²)/.01
Tcos(5.5)=8.53×10^-4                     1.31×10^-7=(9×10^9×q²)
                                         1.50×10^-17=q²

T=(8.57×10^-4)N  Fe=(8.21×10^-5)C        (3.82×10^-9)N/C

Conclusion/Analysis:
In order to get the electroscope to be negative from a positive
vinyl strip, put the vinyl strip close but not touching just ground
the vinyl strip then move the vial strip away and un-ground the
strip.