Speed is the ratio of the distance an object moves to
a. the amount of time needed to travel the distance.
b. the direction the object moves.
c. the displacement of the object.
d. the motion of the object.

The correct answer is A. The amount of time needed to travel the distance

Explanation:

Speed focuses on measuring how fast an object moves through the formula Speed = Distance / Time. For example, if a car traveled 150 km in 3 hours the speed is 50 km/h considering 150 km (distance) divided into 3 hours (time) equals 50km/h (speed). This implies speed considers both the distance the object moves and the time that takes this movement. Moreover, speed does not focus on the direction of the movement or any other factors. Thus, speed is the ratio of the distance an object moves to "the amount of time needed to travel the distance".

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.