A 5.0 kg rock is thrown down at 7.0 m/s from a height of 4.0 m above the floor. What will be its kinetic energy just before hitting the floor?

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.