# Driving around a road block? (Quick, turn the wheel !?) [closed]

Consider a car driving with given speed $v$ head-on towards a road block of a certain width.
Car and road block are already so close to each other that a collision would not be avoidable anymore by either applying the brakes (to achieve maximum decelaration magnitude, given as $a_{\text{max}}$) while continuing to drive straight,
or else by maintaining speed $v$ while steering towards the nearest edge of the road block (turning a circle with maximum centripetal acceleration magnitude, which is also given as $a_{\text{max}}$) .

Does the driver still have any course of action (using the steering wheel as well as the brakes) by which to avoid the collision?,

where the maximum possible acceleration magnitude of the car shall be $a_{\text{max}}$ in any circumstance,
the length or width of the car may be neglected,
and, of course, road block and pavement remain stationary.

(This question came up reading http://scienceblogs.com/builtonfacts/2013/02/27/quick-hit-the-brakes/ .)

-
 Yes if the driver is pretty skilled one he could make a turn to either side while applying the front brake's a few millisecond after turning the steering wheel which will make the car to skid toward's the road block facing the car's side which will create a little bit greater force of friction to stop the car – Akash Mar 7 at 21:01 Two things here. First, this reads like a homework or exam problem and in fact the blog you link to says that it is such. Secondly the blog you linked to has already answered the question. Is there a concept that you have having particular trouble with? It is not that this is a bad question on its own merit or that it is uninteresting, but as per the FAQ "You should only ask practical, answerable questions based on actual problems that you face.". – dmckee♦ Mar 7 at 21:28 @Akash The maximum possible acceleration (or deceleration) wrt. the pavement is set as "$a_{\text{max}}$ in any circumstance", including possbile skidding. (Sure, the question is somewhat contrived in this respect; but otherwise I wouldn't consider this problem answerable, and face it.) So: outright skidding can't be more helpful than plain breaking. And in the given setup, plain breaking is supposed to be not efficient enough to prevent the crash anymore. – user12262 Mar 7 at 22:00 @dmckee "the blog you linked to has already answered the question". No: that blog supposed "a wide wall" whose edges, if any, are of no concern. In contrast, the question stated above requires "a road block of a certain width" (as it tends to occur in actual problems), and refers to "steering towards the nearest edge of the road block" in the setup description. Consequently, that blog neither asked nor answered my question. It merely raised it. Wrt. concepts: my skills/efforts in numerics or differential/variational calculus have so far been inadequate for answering my question. – user12262 Mar 7 at 22:15 @Qmechanic My question has now been tagged as "homework". Which course, taught by whom, should I attend to receive this question as a homework problem and thus have a chance to learn how to solve it? – user12262 Mar 8 at 6:44
show 2 more comments

## closed as too localized by dmckee♦Mar 7 at 21:24

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, see the FAQ.