Kinematics Problem, seemingly missing information

AI Thread Summary
The backpacker walks with an average velocity of 1.36 m/s due west after hiking 5.18 km west at 2.05 m/s and then turning back east. The discussion highlights the need to treat the eastward distance as negative in calculations, emphasizing that average velocity is based on total displacement rather than total distance. Participants suggest rewriting the equation to isolate the distance walked east, incorporating the correct time calculations for both segments of the hike. The problem remains complex due to the interplay of velocities and directions, indicating a potential lack of sufficient information for a straightforward solution. The final equation provided reflects the necessary adjustments for accurate computation.
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.
 
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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.

1.36 = \frac{5180 - Dist}{\frac{5180}{2.05} + \frac{Dist}{.699}}
 
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thanks for the help guys
 
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