quantity of matter
this article is about the scientific concept. for the substance of which all physical objects consist, see
matter. for the main liturgical service in some christian churches, see
mass (liturgy). for other uses, see
mass (disambiguation).
cast iron weight used for
balances – mass: 2 kg (4.44 lb) height: 4.9 cm (1.9 in); width: 9.2 cm (3.6 in)
part of a series of articles about 
classical mechanics 

$\overrightarrow{f}=m\overrightarrow{a}$ 


branches
 applied
 celestial
 continuum
 dynamics
 kinematics
 kinetics
 statics
 statistical

fundamentals
 acceleration
 angular momentum
 couple
 d'alembert's principle
 energy
 force
 frame of reference
 inertial frame of reference
 impulse
 inertia / moment of inertia
 mass
mechanical power
 mechanical work
moment
 momentum
 space
 speed
 time
 torque
 velocity
 virtual work

formulations
analytical mechanics  lagrangian mechanics
 hamiltonian mechanics
 routhian mechanics
 hamilton–jacobi equation
 appell's equation of motion
 koopman–von neumann mechanics

core topics
 damping (ratio)
 displacement
 equations of motion
 euler's laws of motion
 fictitious force
 friction
 harmonic oscillator
 inertial / noninertial reference frame
 mechanics of planar particle motion
 motion (linear)
 newton's law of universal gravitation
 newton's laws of motion
 relative velocity
 rigid body
 dynamics
 euler's equations
 simple harmonic motion
 vibration

 circular motion
 rotating reference frame
 centripetal force
 centrifugal force
 coriolis force
 pendulum
 tangential speed
 rotational speed
 angular acceleration / displacement / frequency / velocity

scientists
 galileo
 huygens
 newton
 kepler
 horrocks
 halley
 euler
 d'alembert
 clairaut
 lagrange
 laplace
 hamilton
 poisson
 daniel bernoulli
 johann bernoulli
 cauchy



mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied.^{[1]} an object's mass also determines the strength of its gravitational attraction to other bodies.
the basic si unit of mass is the kilogram (kg). in physics, mass is not the same as weight, even though mass is often determined by measuring the object's weight using a spring scale, rather than balance scale comparing it directly with known masses. an object on the moon would weigh less than it does on earth because of the lower gravity, but it would still have the same mass. this is because weight is a force, while mass is the property that (along with gravity) determines the strength of this force.