Which One Doesn't Belong? Force and Motion - Questions 4 Help

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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 four similar versions of this question. Each includes four representations. With the exception of the verbal representation, the other three representations will vary from question to question. Two of the versions include:

Version 1:

One of these representations is not like the others. Tap on the one that doesn't belong.

Version 2:

One of these representations is not like the others. Tap on the one that doesn't belong.

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

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 all oppositely-directed forces are of the same strength, then those forces are said to be balanced. In such situations, the object will not accelerate. It will either be at rest or moving a constant speed. Finally, don't be fooled by the "moving to the left" clause. The direction an object moves is NOT related to the direction of the forces. The direction of the forces only affect the direction of the acceleration.

Position-Time Graphs: A straight line on a position-time graph is an indication of a constant velocity value. If the slope is 0 m/s, then the velocity is 0 m/s; that is, the object is not moving. A positive slope is an indication that the object is moving in the positive (rightward) direction. And a negative slope indicates that the object is moving in the negative (leftward) direction. Curved lines indicate speeding up or slowing down motions.

Velocity-Time Graphs: A horizontal line on a velocity-time graph is an indication of a constant velocity value. If the line is located at a velocity coordinate of 0 m/s (on the time axis), then the velocity is 0 m/s; that is, the object is not moving. A horizontal line in the + region of the v-t graph is an indication that the object is moving in the positive (rightward) direction. And a horizontal line in the - region of the v-t graph is an indication that the object is moving in the negative (leftward) direction. Diagonal lines indicate speeding up or slowing down motions.

Verbal Descriptions: Each version of this question has the same verbal description of "The object is moving to the left (- dir'n) with a constant velocity." These words are consistent with any graph or diagram in which the velocity is a constant and negative value.

Dot Diagrams

Position-Time Graphs: Meaning of Shape

Velocity-Time Graphs: Meaning of Shape

State of Motion

Balanced and Unbalanced Forces