Cars a, b, c, d, and e are moving on tracks from left to right. the lengths of the tracks are the same. assuming each car started at the beginning of its track, which cars are moving at a constant velocity? a) a and c b) b and d c) c and e d) d and a

The cars A and C are moving with a constant velocity. The correct option is A.

The diagram attached, is a motion diagram, which marks the positions of an object measured at equal time intervals by means of dots.

If the dots are evenly spaced, it shows that the object is making equal displacements in equal intervals of time, which means that the object has a constant velocity.

In the attached diagram, it can be seen that the dots for the cars A and C are equally spaced, showing that these cars are moving with a constant velocity.

The cars B and D are accelerating, since the space between the dots appears to increase.

The car E is decelerating, as the distance between the dots progressively decreases.

Hence only the cars A and C are moving with constant velocities, with A having a greater velocity than C.

the independent variable, or the one that is intentionally manipulated is the speed.