Does anybody know the empirical formula that relates the initial velocity of a car in a street with the lenght of the mark on ground left by the tires when the brakes are set at maximum force, stopping the wheel ?
The force of friction depends on the coefficient of friction and the normal force. The normal force is just the weight = mg. Thus the acceleration [itex]a = F/m = ( \mu m g)/ m = \mu g[/itex].DaTario said:But the reason it seems to me as a little more envolved problem was the presence of gravity acceleration in the explanation and formula of Mr. Krab.
Yes, it is about 1-1.2 for good tires on hot asphalt. It's quite a bit less (~0.6) if the wheels are locked.DaTario said:Is it true that [tex] \mu [\itex] is 1 in the friction between tires' rubber and the asphalt ?