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Cal and Marty on a 60-mile bike trip with wind and current variables. Solve complex rate of speed problems using algebraic equations. Find boat speed in still water and current rate. Learn to apply constraints and analyze speeds in different scenarios.
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Motion Wind & Water Currents Problem Algebra 1
Cal and Marty are making a 60-mile trip that with no wind they can average 15mi/h on their bicycles, and there is a constant wind of 5mi/h. For half of the round trip they head directly into the wind. Their rate is 15 – 5, or 10 mi/h. For half the trip the wind blows in the same direction they are traveling. Their rate then is 15 + 5, or 20 mi/h.
Rate x Time = Distance 10 30 20 30
30 10 20 30 After the table is completed it can be used find the solutions to several questions that may be asked.
It takes 2 h for a boat to travel 28 mi downstream. The same boat can travel 18 mi upstream in 3 h. Find the rate of speed of the boat in still water and the rate of the current. Problems involving wind and water currents make the rate of speed complex and involve two-variables like the system of equations. Let r = rate of speed of the boat in still water. Let c = rate of current
Rate x Time = Distance r + c 28 r - c 18
Write the Two Constraints Conclusion: The rate of the boat in still water is 10 mi/h. The rate of the current is 4 mi/h.
Mr. Ryan goes white water rafting with his rubber ducky. They go 20 miles per hour upstream until they hit a rock. Then they go twice as fast downstream. How fast is the current? Let r = rate of speed of the boat in still water. Let c = rate of current
Write the Two Constraints Conclusion: The rate of the current is 10 mi/h.
Another fine lesson Given by the great teacher Mr. Stubbs THE END