dennis@home
the brakes use friction to turn kinetic energy to heat
they have a maximum rate at which they can do this..
so as a car travelling twice as fast has four times the energy it takes four
times as long to dissipate the heat in the brakes.
So it takes four times as long to stop.

Hmmm -- I wonder what would happen if car manufacturers decided to
size their brakes such that they could easily dissipate the heat from
say a 100mph to 50mph panic stop. Those same brakes could then also
easily dissipate the required amount of heat from 50mph to 0mph and
thus the vehicle would only take twice the time to stop from the
higher speed rather than four times. In this "new, enlightened
manufacturer" scenario, the limit for typical panic stop would then
not be heat dissipation at the brakes, but rather tire/pavement
coefficient of friction.

Someone should build a car with brakes like this. Oh, wait --
EVERYONE DOES!!!!!!!!!!!!

It really is that simple.. rick doesn't have a clue,

You on the other hand must not have a car. Due to aerodynamic drag,
on the braking limit your car will take less time to brake from 100mph
to 50mph than it will from 50mph to 0mph. Try it with a stopwatch
sometime.