Followers of this blog might have deduced that I live within sight of the sea, which means that it is nearly always windy. After a rain storm the streets of the city are usually littered with broken umbrellas. I suspect that most of these belong to the many tourists that visit Liverpool, because local residents know that the wind will wreck any umbrella that you are brave enough or foolish enough to put up.
It is relatively straightforward to estimate the forces involved in holding an umbrella up in a gale by using control volume analysis. The lesson plan below includes this Everyday Engineering Example together with two more control volume analyses.
The title of the posting is pretty tenuous this week: Gene Kelly sings ‘Singin’ in the rain’ without an umbrella in the film of the same name, see www.youtube.com/watch?v=D1ZYhVpdXbQ – well its difficult to be creative all of the time, or even some of the time!
See also the Everyday Engineering Examples page on this blog for more lesson plans and more background on Everyday Engineering Examples.
Realize Engineering 