The discussion revolves around determining the speed of a car based on the length of its skid mark and the coefficient of friction, following an accident on a level road. The original poster provides specific measurements and equations related to the problem.
The discussion is active, with participants sharing their calculations and questioning each other's results. Some participants express confusion over negative values obtained in their calculations, while others suggest recalculating or reconsidering the approach taken. There is no explicit consensus on the correct answer yet, but some guidance has been offered regarding the equations used.
Participants note that the normal force may not always equal the weight of the car, indicating a potential assumption that needs to be examined. The original poster's approach seems to involve concepts of work and energy, which may differ from kinematic methods discussed by others.
kavipach said:Homework Equations
Fd=-m*vinitial^2/2
kavipach said:it gave me -12..and aparently that isn't the right answer
kavipach said:well the F here is the force which comes from Fn*CoFr=Ff where Fn equals Normal Force CoFr is co. of friction and Fr is force of friction. So if we subsitute F for Fn*CoFf, the masses on both sides cancel out. leaving us with CoFr*g*d=-vinitial^2/2. The by pluging in the values, i got -23 acctually which isn't the answer either.
y2kkmac said:I got, by using Vf2 = Vi2 + 2ad and using the fact that F/m = (coefficient of friction)*g, 24.15 m/s.
EDIT: Whoops, I'm sorry for the bump!