Rate of Current: Solve Homework Equation for US Students

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SUMMARY

The discussion revolves around solving a physics problem involving a canoist rowing upstream against a current. The canoist travels 2 miles upstream, turns around after one hour, and returns to the starting point simultaneously with a log floating downstream. The key variables include the canoist's speed (v) and the current's speed (c). The solution involves setting up equations based on the distances and effective speeds during both upstream and downstream travel, ultimately leading to a system of equations to determine the rates.

PREREQUISITES
  • Understanding of basic physics concepts such as speed, distance, and time.
  • Familiarity with algebraic equations and solving systems of equations.
  • Knowledge of relative motion in fluid dynamics.
  • Ability to visualize problems using diagrams for better comprehension.
NEXT STEPS
  • Study the principles of relative velocity in fluid dynamics.
  • Learn how to set up and solve systems of equations in algebra.
  • Explore real-world applications of current and motion problems in physics.
  • Practice similar physics problems involving upstream and downstream motion scenarios.
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Students studying physics, educators looking for challenging problems, and anyone interested in understanding motion in fluid environments.

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Homework Statement


A canoist is rowing upstream a river. After 2miles he passes a log (traveling with the current) he continues to row for one more hour and turns around. He reaches his starting point at the same time as the log. What is the rate of the current?


Homework Equations





The Attempt at a Solution


v1+v2/c
To be honest I don't even know where to begin with this problem. The teacher gave it to us as a joke because he said this was something from his high school book in Russia and hasn't found anyone in the U.S who can solve it.
 
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Draw a picture.

the start point = 0---------------- log position= 2miles ------------- turnaround point

So suppose the current's speed is c.

What is the position of the turnaround point in terms of c?

Where is the log located when the rower reaches the turnaround point?
 
Assume that the speed v of the canoist (with respect to current) is constant, or the average speed is constant for the different phases of the trip. The current's speed is constant c.

Traveling upstream, the distance traveled is (v-c)*t, and down stream the effective speed is v+c. Knowing the times and distances, one should be able to find two equations to solve to the two unknowns, v and c.
 

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