Summary AP Physics C: E&M - OpenStax University Physics Volume 2, Chapter 5 Problems 39, 49, 52, 55

AP Physics C: Electricity and Magnetism. OpenStax University Physics Volume 2, Chapter 5 Problems 39, 49, 52, 55 with Answers and Work. 39. To start a car engine, the car battery moves 3.75 × 1021 electrons through the starter motor. How many coulombs of charge were moved? 49. Two charges +3 C and +12 C are fixed 1 m apart, with the second one to the right. Find the magnitude and direction of the net force on a -2-nC charge when placed at the following locations: (a) halfway between the two (b) half a meter to the left of the +3 C charge (c) half a meter above the + 12 C charge in a direction perpendicular to the line joining the two fixed charges. 52. Suppose Earth and the Moon each carried a net negative charge -Q. Approximate both bodies as point masses and point charges. (a) What value of Q is required to balance the gravitational attraction between Earth and the Moon? (b) Does the distance between Earth and the Moon affect your answer? Explain. (c) How many electrons would be needed to produce this charge? 55. Two small balls, each of mass 5.0 g, are attached to silk threads 50 cm long, which are in turn tied to the same point on the ceiling, as shown below. When the balls are given the same charge Q, the threads hang at 5.0° to the vertical, as shown below. What is the magnitude of Q? What are the signs of the two charges?