Thursday, March 31, 2011
Question of the Day
That got me to thinking: what's different about the contents of this truck vs. a massive helium balloon? In other words, what keeps this truck from flying? (or, for that matter, the helium tank used to blow up the balloons?)
See if you can answer that using a search engine query. Post your answer in Comments and briefly describe your search strategy.
Be careful, the answers you find online don't necessarily agree.