Name two things in your life that require work. name two things you would use to do work

How many neutrons does element x if it’s atomic number is 28 and its mass number is 87

Select the correct answer. what does the process of natural selection involve?

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.