After VW was outed for falsifying environmental data in its cars hundreds of thousand of VW vehicles were taken off the road now sitting in storage sites. Hundreds of thousands of cars now lie in lots in the Mojave Desert, a shuttered suburban Detroit football stadium, and a former Minnesota paper mill in America alone. These vehicles are now in the open slowly breaking down with pollutants entering the environment. Is the the modern cost of corporate greed? What can we do to ensure this never happens again?
(Score: 2, Interesting) by Anonymous Coward on Sunday December 09 2018, @05:11AM (3 children)
You're dangerously wrong!
> If you just want to stop in a straight line, locking the wheels is the best strategy.
That's not true. The static friction is much lower than the dynamic friction under almost all cases, as the surface rubber softens and road material lubricates the interface. Note that rolling is static friction at any instant (contacting points stay aligned), and skidding is dynamic friction (contacting points on surfaces shift relative to each other).
Locking the wheels is the best strategy under some conditions, but DEFINITELY not in the general case!
Source: lots of easy to duckduckgo theory, and I've confirmed with my own force studies on bike wheels. Setup never included intentional particulate (sand, gravel) or pooled water, but results obtained for slick-wet and dry. Rubber on cement and asphalt and wood produces more backwards force in stiction than in skid.
(Score: 2, Informative) by Anonymous Coward on Sunday December 09 2018, @06:51AM
You missed the context (on purpose?), sorry that I didn't make it painfully clear. I only meant that locked wheels are the best strategy for deformable surfaces - which was the clear topic of my post, this whole thread is in response to Runaway and his gravel road.
What I wrote (and you quoted):
> If you just want to stop in a straight line, locking the wheels is the best strategy.
What I should have written:
> If you just want to stop in a straight line on a deformable surface, locking the wheels is the best strategy.
(Score: 0) by Anonymous Coward on Sunday December 09 2018, @07:01AM (1 child)
> ... my own force studies on bike wheels.
Upright or recumbent bicycle? On an upright, any serious amount of braking on the front wheel leads to pitch over.
(Score: 2) by Reziac on Monday December 10 2018, @12:30AM
Braking my old Schwinn (which was heavy -- 40 pounds on the scale) on ice... had to use rear brake ONLY. Touch the front brake and the whole bike would instantly swap ends, making for an exciting ride...
And there is no Alkibiades to come back and save us from ourselves.