How does velocity differ from speed? what changes in motion can result in a change in velocity?

-Velocity is the speed of any moving object in a given direction, whilst Speed is the rate of an object's ability to move.
-Velocity can change if the direction or time is changed, the basic equation of velocity is: v = d/t
v - velocity
d - distance
t - time
If one of these factors change, it affects the other.

Hope this answers the question!

Any change in motion (direction or speed) is a change in velocity.
Velocity is a vector quantity which means that it has a magnitude and a direction.

Speed, being a scalar quantity, is the rate at which an object covers distance. The average speed is the distance (a scalar quantity) per time ratio. Speed is ignorant of direction. ... The average velocity is the displacement or position change (a vector quantity) per time ratio.