Question

motion is a change in position over time.
there are 3 ways to measure motion: speed,
velocity, and acceleration.
speed is how fast an object is moving. we calculate
speed using the formula: speed = distance/time.
velocity is speed in a given direction.
acceleration can occur when an object speeds up,
slows down or a has a change in direction.
what is the best definition of
motion?
a book sitting on a table
an object is at rest
a change in position over time

Explanation:

The left - hand side of the image clearly states that "Motion is a change in position over time". The first option "A book sitting on a table" represents an object at rest (no change in position). The second option "An object is at rest" also does not describe motion. Only the third option "A change in position over time" matches the given definition of motion.

Answer:

C. A change in position over time