Optimally Dancing to “Shout”

From the dual categories of “Someone Had To Figure This Out” and “Applied Mathematics At Work,” FiveThirtyEight.com has used a little algebra to answer one of our generation’s most vexing questions:

What’s the proper rate of descent during the “a little bit softer now” portion of the song “Shout?”

Here’s the link to the article: http://fivethirtyeight.com/datalab/shout-isley-brothers/

And, in case you haven’t been to a wedding reception recently, here’s the song:

Paths

I offer the following xkcd comic as a possible engagement exercise concerning the Pythagorean theorem.

paths

Source: http://www.xkcd.com/85/

Seismic waves

xkcdseismic_waves

Source: http://www.xkcd.com/723/

green line

The above comic pretty much happened when a 5.8 earthquake hit Virgina in 2011, as people up and down the East Coast received tweets about an earthquake seconds before feeling the earthquake for themselves.

It also inspires the obvious word problem for Algebra I students.

When an earthquake hits, seismic waves travel at about 5 meters per second. Suppose that Alex tweets about the earthquake 30 seconds after feeling its seismic waves. The tweet travels at about 200,000,000 meters per second. How far away does someone have to be from Alex to receive the tweet before also feeling the seismic waves?