what is a reference point?
is a place or object used to determine if something is in motion.
if an objects position changes relative to another object.
a place we refer to when determining if an object is accelerating.
how do you know if an object is in motion?
if it is vibrating.
if the objects beside it move relative to it
if its position changes relative to another object
what is distance?
to describe velocity
to describe motion
is a length of a path between two points
what do we need (si) unit for.
to calculate acceleration.
to know if an object is moving.
to describe motion completely.