Category: Mass, Weight and Density

Density is the mass per unit volume of a substance.

Gravitational field strength is the gravitational force per unit mass (N/kg).

Gravitational field is a region in which a mass experiences a force due to gravitational attraction.

Mass is the measurement of the amount of substance in a body.

Inertia refers to the reluctance of the object to change its state of rest or motion.

The bigger the mass of a body, the greater its inertia.

(ie, the bigger the mass, the more difficult it is to make a stationary object move, or to make a moving object change its speed or direction, due to its inertia)

Mass	Weight
A measurement of the amount of substance in a body.	A measurement of the amount of gravitational force acting on a body
SI Unit: kilogram (kg)	SI Unit: newton (N)
Constant regardless of the gravitational field strength	Varies according to the gravitational field strength
Measured by a beam balance or electronic balance	Measured by a spring balance
Scalar quantity	Vector quantity