SOLUTION: A person travels 136 miles from one town to a city at an average speed of 77 mph and then returns home at an average speed of 56 mph. What was the average speed over the total di

Question 547710: A person travels 136 miles from one town to a city at an average speed of 77 mph and then returns home at an average speed of 56 mph.
What was the average speed over the total distance covered?
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
A person travels 136 miles from one town to a city at an average speed of 77 mph and then returns home at an average speed of 56 mph.
What was the average speed over the total distance covered?
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Avg speed of a round trip is 2*R1*R2/(R1 + R2) R1 & R2 are the 2 rates.
I worked this out some time ago while looking at the Michelson-Morley experiment.
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It's similar to parallel resistors and parallel flows, but with a factor of 2.
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Avg speed of the round trip = 2*77*56/(77+56)
=~ 64.84 mi/hr

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