Mass

Mass is a scalar quantity measured in kilograms (kg). Unlike weight, mass does not change with location. An object has the same mass on Earth, on the Moon and in space.

Mass determines:

• how much an object resists acceleration (inertia): $F = ma$
• the gravitational force between objects
• the density of an object: $\rho = m/V$

Mass is measured using a balance (comparing masses) or an electronic scale.