Yet another weird SF fan
 I'm a mathematician, a libertarian, and a science-fiction fan. Common sense? What's that?Go to first entry

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 Yet another weird SF fan

### Help! Help! I Was Run Over by a Cupcake!

As is well known, physics can give counter-intuitive results. As is not so well known, that can happen even in the mundane parts of physics.

For example, let us calculate the energy of a two-ton automobile traveling at 55 mile/hr. This is 24.5 m/s. If two tons is 1800 kg, the standard formula $$\frac{mv^2}{2}$$ gives 540,225 J. So far so believable. The counter-intuitive part comes in when we try translating that into Calories. At 4184 Cal/J, 540,225 J becomes 130 Calories, about as much as a large cookie or small cupcake.

No wonder overeating is so dangerous…

Cambias said...

What it proves is how immensely inefficient humans (and other animals) are at converting chemical energy to mechanical energy. With the sugar in a can of Coke I should be able to launch the empty can into orbit, but I can barely get it across the room to the trash bin.

. . . which is why any plan to improve "energy efficiency" that involves human-powered transport like bicycles or rickshaws is hilariously stupid.

8:44 AM
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