Models are particularly useful in relativity and quantum mechanics, where conditions are outside those normally encountered by humans. what is a model?

A model is defined as a structure used to represent an object, usually of a different scale.

Explanation:

In quantum mechanics and particle physics, many of the particles are subatomic, meaning that they are smaller than atoms. This is where a model would be useful. A model could help people to visualise what the particle looks like, and in general would make it easier to understand the behaviour of such a particle.

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.