[Swizec]

> The blue car, using ½mv², shed (~70²=) 4900 units of energy (we'll hand wave away the constants). So the red car, which had (100²=) 10000 units of kinetic energy to start, also shed 4900 units, which means it had 5100 units of energy when it collided, and so was going (√5100~) 71

But if the cars produce downforce this is no longer true because you brake harder (more friction available) at higher speeds!

This is how F1 cars pull 4G when breaking. Some custom cars (like one of Ken Block’s last monsters or the Valkyre) use active aero braking to even greater effect.

[chrisweekly]

1. +1 insightful, thanks for sharing your physics knowledge

2. I know you know this, but for the sake of others, it's when _braking_ (applying the brakes), not _breaking_ (becoming broken).

I'm not a pedant. But these errors jump out at me and I'm always a bit surprised and dismayed at this dichotomy; in our field, somehow the requisite attention to detail, the precision inherent to communicating scientific concepts, code, algorithms and formulae, is so often just abandoned when it comes to prose.

[tracerbulletx]

But what if the cars are spherical cows?

[kibwen]

I'm sorry to inform you that those cows are going to have a hard time braking on that frictionless surface.

[PaulDavisThe1st]

Based on a hike in the Carson National Forest 2 days ago, the only reason a cow is on a frictionless surface is that the cow shat all over it.

[BigTTYGothGF]

Cows can't roll that fast.

[zdragnar]

Not with that attitude

[elromulous]

Or on shabbos