ELECTRIC POTENTIAL DIFFERENCE EM 17 I. Work and electric potential energy In the tutorial Conservation of energy, you found that the net external work done on a system is equal to the change in total energy of that system. For a system that can be treated as having only kinetic and potential energy, this can be expanded as: Wnet ext = AEtot = AK + AU. Two experiments are conducted with identical blocks on a level, frictionless surface. The blocks experience an Experiment 1 attractive conservative force toward each other (not Each block begins shown). and ends at rest. t = t In experiment 1, the hands allow each block to move a distance do toward the other. The blocks start and end at rest In experiment 2, the hands release the blocks from rest. Each block has a speed of Un after moving a distance do t= t, A. Is the net external work done on the system of both A m blocks in experiment 1 positive, negative, or zero? Explain your reasoning. e. It is rey united Experiment 2 Each block begins at rest B. Is the net external work done on the system of both and ends with speed ,2 blocks in experiment 2 positive, negative, or zero? t = t; Explain your reasoning. t = t C. In the table below, indicate if each quantity is positive, negative, or zero for each experiment. Complete the table from left to right. m Wnet ext AEtot AU Experiment 1 Experiment 2 Potential energy is an internal property of a system, caused by a conservative force. If two systems experience identical changes in position, caused by identical conservative forces, AU for each system will be the same. D. Are your results from the table above consistent with this definition? Tutorials in Introductory Physics, Physics Education Group, Department of Physics University of Washington (Summer 2022, Mazur version)