j***@gmail.com

2017-02-19 18:31:17 UTC

Permalink

The latest xkcd What-If https://what-if.xkcd.com/154/ asks if we could coast (on a bicycle) from the West coast to the East coast of the US, by building a suitable slope.Raw Message

The answer involves some physics and, of course, some formulas. Let me copy from the page source:

<p>\[ \text{Forward pull from gravity} = \text{Rolling resistance} + \text{Drag force} \]</p>

<p>\[ m g \sin(\theta) = g \cos(\theta) C_r m + \tfrac{1}{2} C_d \rho A V^2 \]</p>

<p>\[ V = \sqrt{\frac{m g \sin(\theta) - g \cos(\theta) C_r m}{ \tfrac{1}{2} C_d \rho A}} \]</p>

The xkcd web page uses MathJax to render these LaTeX-notation formulas. There are a lot of pages that do this sort of thing.

Oh, by the way, the math works out that LA to NY would mean starting at least 5 miles up. So sadly not possible. But there is the 35 mile Haleakala downhill bike ride in Hawaii.

I think it's very good that LaTeX (via MathJax) can be used to put math on web pages. I'd like us to make more of this, when we develop and promote TeX.

What do you think?

--

Jonathan

Jonathan