LAB ACTIVITY  Relationship between Force and distance
Purpose: Find relationship between electric force and distance (radius) from two charges (balloon and rod).Measurement from video:Distance (radius) = measurement from end of rod to center of balloonForce = measurement displacement of center of balloon from center of blue sticky note on wall.Data: Radius(mm) "Force"(mm)Graphs:Graph #1  Radius (on xaxis) vs. Force (on yaxis)  Will not be a linear relationship.Graph #2  1/Distance vs. ForceGraph #3  1/Distance^2 vs. ForceCalculations  Take the y = mx + b formula from final graph and rewrite to show graph variables and units.Questions:1. Compare the slope from your graph to other groups. Why is there a variation?2. How does this lab relate to the formula for Coulomb's law?3. What is k and why is it needed in the formula?4. What is a coulomb of charge?5. What was the type of relationship found between electrical force and distance?6. Where else in physics does an "inversed squared" relationship exist?ConclusionStandard  Restate purpose, list results (include relationships and mathematical findings), discussion to prove your results and statement of errors (be specific).Purpose, result, discussion, errors.
