The energy associated with the motion of particles in a substance is called

heat

Explanation:

Heat is what a living being feels at a high temperature. Physics understands heat as the energy that is transferred from one system to another or from one body to another, a transfer linked to the movement of molecules, atoms and other particles.

It is important to keep in mind that bodies do not have heat, but internal energy. When a part of this energy is transferred from one system or body to another that is at a different temperature, it speaks of heat. Heat transfer will occur until the two systems are at the same temperature and the so-called thermal equilibrium is reached.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

be subject to a force andchange its motion