Forces, when unbalanced, cause an object to change its state of motion - to speed up, to slow down, or to change direction. But when the forces are balanced, an object in motion will continue moving with the same velocity and an object at rest will remain at rest with a velocity of 0 m/s. There are many ways to represent such at-rest, constant velocity, and changing velocity motions. The task is to relate the force information to the motion representations and identify the one representation that is a mis-match.
 

There are five representations. You must choose which one is NOT consistent with all the others. Here's information about each representation:

Dot Diagrams: Each version of this question has the same dot diagram. The diagram shows dots whose spatial separation is decreasing as the object moves to the right. This represents an object moving to the right (+ direction) and slowing down.

​Force Diagrams: When considering how an object will move - whether it will accelerate or move with a constant speed and direction, it is important to compare the strength of the forces that act on the object. If oppositely-directed forces are not equal strength, then the object accelerates. If the right force is stronger than the left force, then the object is either moving to the right and speeding up or moving to the left and slowing down. Both are equivalent to a rightward acceleration. If the right force is weaker than the left force, then the object is either moving to the right and slowing down or moving to the left and speeding up.  This is referred to as a leftward acceleration.  If all oppositely-directed forces are of the same strength, then the object will not accelerate. Finally, don't be fooled into thinking that a rightward-moving object must have a rightward force or even more right force than left force. There's no such "rule." A rightward-moving object only needs more right force than left force if it is speeding up.

Position-Time Graphs: A curved line on a position-time graph is an indication of a changing velocity. If the line slopes upward, then the velocity is positive (rightward); if the line slopes downward, then the velocity is negative (leftward). If the line is getting steeper over the course of time, then the object is speeding up. If the line is becoming less steep (i.e., flatter) over the course of time, then the object is slowing down. A straight, diagonal line is an indicator of a constant velocity motion.

Velocity-Time Graphs: A diagonal line on a velocity-time graph is an indication of a changing velocity motion. A line in the + region of the v-t graph is an indication that the object is moving in the positive (rightward) direction. And a line in the - region of the v-t graph is an indication that the object is moving in the negative (leftward) direction.  Lines that are heading away from the time axis represent speeding up motions. And lines that are approaching the time axis represent slowing down motions. A horizontal line is an indicator of a constant velocity motion.

Velocity-Time Tables: An accelerating object has a changing velocity. One way to represent this is with a velocity-time table. If the velocities in the table are listed as + velocities, then a rightward motion is being represented. Negative velocities are used for a leftward motion.  The absolute value of these velocities are indicators of speeds. If the absolute values are becoming larger, the object is speeding up. A slowing down motion is represented by absolute values that are becoming smaller.