When waves of equal amplitude from two sources are out of phase when they interact it is called?

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.