This question relates to the practicality of searching for intelligent life in other solar systems by detecting their radio broadcasts (or aliens find us from ours). the closest stars are 4 light years away from us. how far away must you be from a 475 khz radio station with power 50.0 kw for there to be only one photon per second per square meter? assume that the photons spread out spherically. the area of a sphere is .

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.