Dam It, We’re Learning Here!

A group of kids huddled around a garden hose may look like a recipe for disaster, but in this case it was to prove a point about pressure. The question started off innocently enough: “What would have more pressure, the bottom of a hose that was held off a cliff, or the plug at the bottom of an Olympic swimming pool?”. Sure, one has about a gazillion times the amount of water behind it, but does that really matter when it comes to pressure? Well, to put it to the test we filled up our 20m long garden hose and I got the kids to walk down the path, which descends vertically fairly quickly. 20m of hose… that has to have a bit of water in it, yeah? It should start to really gush by the time they get to the bottom of the hill. Sure enough one kid after the next wandered down the path only to find the task of holding the hose clamped shut harder with each step down. Continue reading