Q- Why did the balloon bombs launched by japan, failed as effective weapons against america?
Answer:
They were ineffective weapons because:
The major reason for it's ineffectiveness lay in the fact that they had a very low success rate. They killed only six people and caused only a small amount of damage which amounted to a kill rate of 0.067%.
The expense required in the preparation of these balloons was large.
The preparations were lengthy because the technological problems were acute. A hydrogen balloon expands when warmed by the sunlight and rises, then it contracts when cooled at night, and falls.
America always knew that japan had been working on biological weapons and therefore somewhat anticipated such an attack.