a property of matter by which it continues in its existing state of rest or uniform motion in a straight line unless that state is changed by an external force.

_____ is the amount of matter or substance that makes up an object.

the rate of change of velocity per unit of time.

___ ____ is the vector sum of forces acting on a particle or body.

___ ____are two forces acting in opposite directions on an object, and equal in size.

When two forces acting on an object are not equal in size, we say that they are____ _____.

________ is a physics term; it refers to the quantity of motion that an object has.

the SI unit of force.