Have seen a car accident, if the skid mark left by the tyres is 18 meters long before impact ,?

Question

how fast do you estimate the vehicle was going

Answer 1

speed = sqrt{2*retardation by brakes*distance it took to stop}

Answer 2

way to fast the car did NT stop in time so the speed was to excessive

Answer 3

www.easts.info/on-line/journal_06/3401.p...

Copy and paste above and it gives you the equation you require including weather conditions, ABS and make/model of vehicle.

Answer 4

The decelerating force is m*g*µ, where µ is the coefficient of friction of tyres on the ground.  The deceleration is F/m, so

a = g*µ

the velocity is v = √[2*a*d], where d is the distance traveled.  if we take µ = 0.6 (just a guess) then v ~ 15 m/s or ~ 55 km/hr

Answer 5

18 metres?.....................way too fast!

120 mph?

Answer 6

the police have accident investigatore trained to know these things. if youve seen it you must have an idea of how fast??