Resultant displacement with multiple segments

AI Thread Summary
John's resultant displacement from the 233-mile marker is calculated by considering his movements: he travels 78 miles back (from 233 to 155) and then 17 miles forward (from 155 to 172), resulting in a total displacement of -61 miles. Bob's displacement, after walking 57 meters east and then 125 meters west, is -68 meters, indicating he has moved past the origin. Both problems highlight the importance of including direction in displacement calculations, as displacement is a vector quantity. The discussion emphasizes that neglecting the negative sign can lead to incorrect answers. Understanding vector direction is crucial for accurate displacement results.
Kdawg
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I have to displacement problems that i can't get right.

While John is traveling along a straight interstate highway, he notices that the mile marker reads 233. John travels until he reaches the 155-mile marker and then retraces his path to the 172-mile marker. What is John's resultant displacement from the 233-mile marker?
I thought the answer for this one would be 61 but it is marked wrong.

Bob walks 57 m and then he walks 125 m. What is Bob's displacement if he walks east then west?
I thought the answer for this one would be 68 but it is marked wrong.
 
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For the second problem, Try negative -68, cause he goes past the origin, to the negative side. Also, the first answer may be negative also, not sure though.
 
Thanks, that was it. for some reason I was thinking displacement couldn't be negative.
 
displacement is a vector quantity. all vector quantities are affected by direction. therefore all vector quantities should be labeled with a direction (wether it be shown with a positive/negative sign, bearing on a compass,etc)
 
Kdawg said:
I have to displacement problems that i can't get right.

While John is traveling along a straight interstate highway, he notices that the mile marker reads 233. John travels until he reaches the 155-mile marker and then retraces his path to the 172-mile marker. What is John's resultant displacement from the 233-mile marker?
I thought the answer for this one would be 61 but it is marked wrong.

Bob walks 57 m and then he walks 125 m. What is Bob's displacement if he walks east then west?
I thought the answer for this one would be 68 but it is marked wrong.

Both answers would have been correct had you included the negative sign for both. :smile:
 
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