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Setting a Flight Plan

This exploration is based on a problem taken from a text written during WWII...

Task 1: Solve the problem.

Does it take an aviator the same time to travel 2 miles, (a) when he goes the first mile at 60 miles per hour and the second mile at 120 miles per hour, as (b) when he travels the 2 miles at 90 miles per hour?

Task 2: Explain conceptually why your results make sense.

Task 3: In this adjusted problem, find the value of X that would make (a) and (b) have equal times.

Does it take an aviator the same time to travel 2 miles, (a) when he goes the first mile at 60 miles per hour and the second mile at 120 miles per hour, as (b) when he travels the 2 miles at X miles per hour?

 

Source: J. Moore & j. Mira, The Gist of Mathematics, 1942, p. 15


Hint: Draw a diagram...

Remember the classic D = RT formula...

 


Solution Commentary: For (a), time t = (1 mile)/(60 mph) + (1 mile)/(120 mph) = ?

For (b), time t = (2 miles)/(90 mph) = ?

And, you are on your own with the remainder of the problem...