Primary purpose of this lecture is to present on Mass and Weight. Mass is the quantity of matter in an object. It is also the measure of the inertia or sluggishness that an object exhibits in response to any effort made to start it, stop it, or change its state of motion in any way. Weight is the force upon an object due to gravity. Mass is a measure of the inertia of a material object. Unit of measurement is the kilogram. Weight is the force on an object due to gravity. Scientific unit of force is the newton (N); Unit is also the pound (lb).