Distance traveled using velocity

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SUMMARY

The problem involves calculating the distance a dog travels while its two owners walk toward each other. The owners are initially 10.0 meters apart, walking at a speed of 1.3 m/s, while the dog runs at a speed of 3.0 m/s. The correct approach involves determining the time it takes for the owners to meet, which is 6.5 seconds, leading to the dog traveling a total distance of 11 meters, not 19.5 meters as initially calculated. The confusion arises from misapplying the distance formula and not accounting for the relative motion of the owners.

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  • Understanding of basic kinematics, specifically distance, speed, and time relationships.
  • Familiarity with average velocity calculations.
  • Knowledge of relative motion concepts in physics.
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  • Learn how to apply the distance formula: Distance = Speed × Time.
  • Explore examples of problems involving two moving objects approaching each other.
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destinc
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1. A dog runs back and forth between its two owners, who are walking toward one another. The dog starts running when the owners are 10.0m apart. If the dog runs with a speed of 3.0m/s, and the owners each walk with a speed of 1.3m/s , how far has the dog traveled when the owners meet?


My attempt:
I know each owner will travel a distance of 5m at 1.3m/s which equals 6.5s of time. The dog travels 3.0m/s for the 6.5s= 19.5m traveled, but the answer given is 11m. What am I doing wrong?
 
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destinc said:
I know each owner will travel a distance of 5m at 1.3m/s which equals 6.5s of time.
How far do you travel in 6.5 sec if you go at 1.3 m/sec?
 
destinc said:
1. A dog runs back and forth between its two owners, who are walking toward one another. The dog starts running when the owners are 10.0m apart. If the dog runs with a speed of 3.0m/s, and the owners each walk with a speed of 1.3m/s , how far has the dog traveled when the owners meet?My attempt:
I know each owner will travel a distance of 5m at 1.3m/s which equals 6.5s of time. The dog travels 3.0m/s for the 6.5s= 19.5m traveled, but the answer given is 11m. What am I doing wrong?

Hey physics problems can be tough to get thru sometimes.

You can use an equation that relates velocity, time, and distance to get your answer.

Remember, Average velocity = Δx divided by Δt...where x is displacement and t is time. The trick here is also that you have two people moving at the same velocity closing a distance of 10m.

Once you have the time it takes for these two people to meet, solve for the Δx of the dog.
 
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destinc said:
My attempt:
I know each owner will travel a distance of 5m at 1.3m/s which equals 6.5s of time.✗[/size][/color]
...
 
You can also simplify the problem by treating one owner as being stationary and the other moving at 2.6m/s

EDIT: I got 11.5385, which I think you should round up...not quite sure about this method
 
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