Answer:
18. Direction.
19. Speed.
20. Speed.
Explanation:
Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.
Mathematically, velocity is given by the equation;
[tex]Velocity = \frac{distance}{time}[/tex]
Because the velocity of an object depends on direction as well as speed, the velocity of an object can change even as the speed of the object remains constant. Thus, the velocity would change only when the direction or speed of the object changes.
