mass
amount of matter in an object, independent of its size or any forces acting on the object
both a property of a physical object and how resistant an object is to acceleration (si units of kg)
inertia
the tendency of an object to remain at rest or remain in motion; measured by mass
weight
force of gravity on an object; depends solely on the value of g
external force
a force acting on an object from the outside, as opposed to forces acting within the object
Fnet
the vector sum of all external forces