Master Bernoulli’s principle and expand the bag with a single breath using air pressure.
Here’s the challenge … How many breaths would it take to blow up a 8-foot-long bag? Depending on the size of the person, it may take anywhere from ten to fifty breaths of air. At the end of the challenge, the person is totally out of breath, wondering why she said yes in the first place. Now imagine the look on her face when you are able to inflate the giant bag using only one breath of air. That’s right … one breath and you win! This is one of my all-time favorite science demonstrations, and it’s guaranteed to make it into your Top Ten list.