# Watch out! I’m a blue whale and I’m about to land on you!

I don’t know why this question popped into my head, but it’s been sitting there for the past week and showing no signs of moving on.

Suppose an enemy of mine threw a friendly blue whale at me. Being a friendly whale, it makes the blue-whale-noise equivalent of “DUCK!” to warn me it’s coming.

How quickly does the whale need to be travelling for its warning to be useful?

# Puzzlebomb – November 2014

Puzzlebomb is a monthly puzzle compendium. Issue 35 of Puzzlebomb, for Novmber 2014, can be found here:

Puzzlebomb – Issue 35 – November 2014

The solutions to Issue 35 will be posted at the same time as Issue 36.

Previous issues of Puzzlebomb, and their solutions, can be found here.

# Apparently I’m not a maths genius (or, On the Subject of Parcel Sizes)

Somewhere in the middle, it says that myHermes requires the “volumetric area” of a parcel to be less than 225cm. That’s right: the “volumetric area” is neither a volume nor an area but a length. Anyway, the formula for volumetric area of a package with sides $a,b,c$, where $a \leq b \leq c$, is

$2(a+b) + c$

(Importantly, $a$ and $b$ are always the two shortest sides of the package)

So the constraint is

$2(a+b) + c \leq 225$

In the next paragraph is the puzzling statement that the maximum allowable volume for a package is $82.68$ litres, or $82680$ cm3. How did they get that?

I decided to do some calculus of variations, or whatever it’s called.

# There’s a new StackExchange site for History of Science and Maths

Just a little note to let you know that there’s a new StackExchange Q&A site for “History of Science and Maths”. Some of the maths questions that have already been asked include:

So if you’ve got a burning question about Maths in the Past, there’s now a place to ask it.

Visit the site: hsm.stackexchange.com