What are the two steps required to charge an object without any physical contact between charged objects

Avalue that describes how heavy an object is and is related to the force of gravity is

Two waves maximally constructively interfere at a point in space. among the options below, select the possible value of their phase difference at that point in space.a. zerob. πc. π/2d. not determinable by the information provided

Does the earth behave like a magnet how do you prove it