PHY-104 Lab Report Tips for the Coulomb’s Law Investigation Charge Separation RCorrected, cm Format Title Page 1. Introduction a. Statement of Purpose or the goal of the investigation b. Brief description of Coulomb’s Law including a brief biography of August Coulomb (See Wikipedia). This section need be only 10 or so sentences long. c. A brief description of the experimental set up, including a labeled diagram that identifies the data parameters A0, A and B, and a derivation demonstrating that we can use the distance D as a proxy for the electrostatic force. 2. Data 3. Analysis a. A Graph (#1) of D (y-axis) versus R (x-axis) with a power law trend line. b. A Graph (#2) of D (y-axis) versus RCorrected (x-axis) with a power law trend line where RCorrected represents a reasonable “correction” for the effect of polarization on the two charged spheres as they approach each other. 4. Discussion and Conclusion a. Discuss Graph #1 and relate it to your purpose or goal. b. Discuss the phenomena of polarization and describe how you reasonably “corrected” the R values to account for polarization. c. Discuss Graph #2. d. A summary statement that addresses the purpose or goal of the investigation. Tip on correcting for polarization of the two spheres. 1. A reasonable correction to include the effect of polarization of the two conducting charge-carrying spheres would assert that a. There is no polarization when the spheres are farthest apart. (This probably is not completely true but it is a good starting point.) b. The degree of polarization increases as the two charged spheres get closer (i.e. R gets smaller). A reasonable starting point is that the polarization increases linearly as the separation decreases. c. The maximum polarization occurs when the spheres are closest. At this minimum separation the center of charge on each conducting sphere is shifted away from the geometric center of the sphere by an amount no more than the radius of the sphere. The shift from the geometric center may be less, but not more than the radius of the spheres. d. You must determine how to Experiment on Coulomb's Law 14.0 “correct” the 12.0 separation of the 10.0 spheres to model the separation of 8.0 charges. You will 6.0 Charge Separation find Wikipedia’s 4.0 Sphere Separation Two-Point Form of 2.0 a Linear Equation 0.0 helpful. The result 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Sphere Separation R, cm you are looking for is illustrated