Lab Analysis #1 _ Coulomb's Law Derivation
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labreport1-xxx1.docxXiming Shen
PHYS&222
Lab Analysis #1
1/22/2018
Lab 1.2 Coulomb ‘s Law
1. Introduction
The aim of the experiment is to practice Coulomb’s Law. More specifically, it is to visualize that the same charge repels each other and opposite charge attract each other. And try to find the mathematical relationship between the distance of two charge and the static electric force.
2. Methods
In this lab, we used a pre-recorded video to continue testing the Coulomb’s Law. We downloaded a short movie from canvas then imported it into the Logger Pro. We set the initial position of the suspended ball as zero. Then we played the video frame by frame and mark the location of attached ball as q2 and the other as q1. We calculate the distance between q1 and q2 as r, and calculate the Felec. Recorded them into Excel.
3. Data
4. Calculations
Math Model
R=0.0006f^-0.783
General expression
R=k/Felet
For the electric force
Felet=k*（q1*q2)/r^2）
The charges on each object use last equation
(.0001167594*(q^2) *8.99*10^9)/0.490103852^2
=6.691716035*10^-8 C
5. Results and Analysis
In the second lab, we got a lot of useful data. The type of model looks like intercepts because distance closer, force larger. The interaction between the two stationary point charges is proportional to the product of their charge quantities, inversely to their distance of two times, and the direction of the force is in their connection, the same charge repels, and the name of the charge is absorbed.
Position， q1Position， q2distance, rFelec
0.001945522-0.5583647020.5603102242.79319E-05
0.005836565-0.519454270.5252908358.37959E-05
0.01167313-0.4785983160.4902714460.000167594
0.01167313-0.4338513190.4455244490.000167594
0.015564173-0.3891043220.4046684950.000223462
0.019455216-0.3540849330.3735401490.000279332
0.021400738-0.3093379360.3307386740.000307268
0.023346259-0.2762640690.2996103280.000335205
0.029182824-0.2392991580.2684819820.000419022
0.033073867-0.2003887260.2334625930.000474906
0.036964911-0.1712059020.2081708120.000530796
0.04863804-0.1420230780.1906611180.000698503
0.04863804-0.1108947320.1595327720.000698503
0.058365648-0.0758753430.1342409910.000838313
0.068093256-0.0525290830.120622340.000978182
0.081711908-0.0252917810.1070036890.001174118
