Kinematics Problem, seemingly missing information

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Homework Help Overview

The discussion revolves around a kinematics problem involving a backpacker's average velocity and distance traveled in different directions. The original poster presents a scenario where the backpacker hikes a certain distance west and then turns around to walk east, seeking to determine how far she walked east.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants explore the relationship between average velocity, distance, and time, with some questioning the sufficiency of the provided information. Others suggest rewriting the equation to clarify the relationship between the distances and velocities involved.

Discussion Status

There is an ongoing exploration of the problem, with participants offering alternative formulations of the equations. Some guidance has been provided regarding the treatment of velocity as a vector and the distinction between total displacement and total distance.

Contextual Notes

Participants note potential constraints regarding the information given, particularly in relation to the total distance and time needed to solve for the eastward distance.

mcode
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Homework Statement



In reaching her destination, a backpacker walks with an average velocity of 1.36 m/s, due west. This average velocity results, because she hikes for 5.18 km with an average velocity of 2.05 m/s due west, turns around, and hikes with an average velocity of 0.699 m/s due east. How far east did she walk (in kilometers)?

Homework Equations



avg. v = distance/time

The Attempt at a Solution



the closest i was able to get to a solution was

1.36 = (5180 meters + distance of second part of walk)/(2526.829268 + time of second part of walk)

as far as i can tell, there doesn't seem to be enough information for me to figure out the question.
 
Last edited:
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mcode said:
1.
1.36 = (5180 meters + distance of second part of walk)/(2526.829268 + time of second part of walk)

as far as i can tell, there doesn't seem to be enough information for me to figure out the question.


Rewrigh the above step as
1.36 = (5180 meters + distance of second part of walk)/(2526.829268 +
distance of second part of walk/0.699) and solve the equation for distance of the second part of walk.
 
rl.bhat said:
Rewrigh the above step as
1.36 = (5180 meters + distance of second part of walk)/(2526.829268 +
distance of second part of walk/0.699) and solve the equation for distance of the second part of walk.

You need to remember that velocity is a vector, and that Avg velocity in this case is total displacement from the start - not total distance - divided by the total time.

The eastward walk after the westward should be treated as minus not plus, even though its contribution to total time will be plus.

[tex]1.36 = \frac{5180 - Dist}{\frac{5180}{2.05} + \frac{Dist}{.699}}[/tex]
 
Last edited:
thanks for the help guys
 

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