Exploring Electric Potential When answering questions, say it well but say it briefly INCLUDE YOUR GRAPH FOR PART 2 Part 1 What is an equipotential line and how is this simulation related to work and energy 1) Go to the PhET simulations. (phet.colorado.edu) 2) From the list on the left choose Electricity, Magnets, and Circuits. 3) Now pick Charges and Fields. 4) Turn on Show Numbers 5) Place a positive 1 nano-coulomb charge near the center of the screen. 6) In the lower left of the screen is a meter for indicating electric potential, in volts, created by the charge that you introduced. Record the voltage and turn on Plot. 7) This line is much like a line on a geologic topo map. Explain the similarity. 8) You are on the side of a hill with a topo map of the region. If you walked so that your trip follows a topo line you would be doing no work on your backpack. Why. 9) If a second charge were placed on this line (dont do it), how much work is need to move it along the line 10) Move the meter closer to the charge at the center of the screen. What is the new electric potential Turn on plot again 11) Remember that electric potential is energy per charge (1 volt 1 Joule/Coulomb). Is electric potential a vector or a scalar 12) If a second positive charge were introduced and moved from the first equipotential line created to the second line (closer to the charge), would this involve positive or negative work 13) Explain. 14) If the second positive charge were moved away from the first Positive charge, would this involve positive or negative work. 15) Click on Clear All Part 2 What is the relationship between the electric potential at a point in space and the distance from an electric charge Place a positive 1 nano-coulomb charge on the screen. Turn on Show numbers Turn on tape measure. Use the tape measure to find and record the distance from the charge to the equipotential sensor. Record the voltage as indicated on the equipotential sensor. Change the location of the positive charge to at least six widely different distances from the equipotental sensor. Record the voltage reading and distance at each location. Use Excel to graph these data sets. Include your graph to turn in with this handout. (all graphs need a title, axes labeled and units) What is the mathematical relation between these variables (hint use power trend