Wednesday, August 17, 2016

The Math of Japanese Balloon Bombs in World War II

Hot Air Balloon Ride, Balloon, Fire  Another activity I had students work on during the cross curricular unit had to do with the balloon bombs Japan used in World War II.

There are so many possibilities for math with this topic.

1.  These balloons traveled from Japan to Alaska, Canada, Washington, Oregon, all to way inland to the Great Lakes Region just using the Jet Stream.  This article has a great map.  Using google and math it would be possible to calculate how long it would take the balloons to travel from Japan to specific locations.   The article states it took between 30 and 60 hours for the balloons to travel across the pacific.  Students can also calculate the ratio of balloons reported versus balloons released.

2.Give the students the volume and diameter  of the balloons and have them calculate how much material was needed to make the balloon for one and then for all the balloons.  The balloons were 33 feet in diameter when fully inflated to carry 19,000 cu ft of hydrogen.  At first they used silk but later used a specific type of paper.  In addition, the balloon itself weighed 152 lbs.  

3.  The Japanese used sand for ballast in the balloons from a beach near Tokyo.  Each balloon had 32 bags of sand weighing 155 lbs. Students could find the average weight of each bag of sand.  Most balloons held one 33 lb bomb, four incendiary bombs (11 lbs each).  In addition, each balloon carried 44 lbs of flight equipment.  So how much weight was taken up by the sand, bombs and flight equipment.

4.  The flash bomb fuse 64 feet and took 82 minutes to burn.  How many feet per minute is that?

If you check this paper out, it has pictures and tons of technical information so you could create a worksheet of questions on this topic alone. Or you could assign groups to read the paper and prepare math questions for others to answer.  This has tons of possibilities.

Have fun.