A type of magnet that is created by wrapping could of wire around a soft iron core and attaching it to the battery a. electromagnet
b. solenoid

The air that we breath is made mostly of which gaseous molecule

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.

The movement of electrons between atoms is called an