Thread by @BostonArchaeo

An important math lesson from your local Boston #archaeology team. Like many of you, we were wondering how many Dunkies medium iced coffees (extra extra) would take to fill in the Mary L. Pierce well in Ronan Park, aka the #DorchesterSinkhole. Well, your wait is over. 1/

Someone shovel off the @DotSinkhole so they can hear this, this is important. 2/

As every news outlet in the region has reported, the Dorchester Sinkhole in fact a 19th century well built around 1818 or 1872 that was buried under a bunch of fill to make Ronan Park around 1912. Yeah, old news. 3/

Its historic well cover recently failed, apparently, and after a recent rain storm, the loosened fill slumped down into the well opening a sink hole in the park. Let’s start with the easy part. The well itself is 2.5 wide by 6.5 feet deep (it partially filled up with the dirt 4/

We all remember that the volume of a cylinder is πr²h. (That’s pronounced “pie-ah-sqwahd-aych”), so the well is π*1.25²*6.5 or 31.91 cubic feet.
Cool.
5/

Now the hard part: the fill on top. A cone’s volume is ⅓ the volume of a cylinder of the same radius, but this ain’t. no. cone. This is a CONICAL FRUSTRUM, people! That’s a cone without the pointy bit. 6/

The volume of a frustum is (1/3) π h (r1² + r2² + (r1 * r2)). Stay with me, folks. R1, the top of the hole is 2’. R2 is the top of the well, 1.25’. H is 10, so the volume of the frustum is (1/3) * π * 10 * (2² + 1.25² + (2 * 1.25)) or a whopping 84.43 cubic feet. 7/

Add them together (31.91+84.43) and the #Dorchester sinkhole is 116.34 ft³ big.
Now for the important part. A medium iced coffee is 24oz. or 0.025 cubic feet. 8/

If we divide the hole’s volume by a single medium coffee (116.34/0.025), you find out you will need 4,653.6 Dunkies medium iced coffees to fill the Dorchester hole.
Now you’re wicked smaht.
9/

What else would it take to fill it? Does anyone know the volume of David Ortiz?
Happy holidays. Go Pats!
10/end