An officer is investigating an accident. A car has struck a pedestrian at a school crosswalk.There are no witnesses to the accident. The officer measures the coefficient of friction at the accident site to be 0.55, and he measures skid marks that are 52m long. What is the minimum initial speed of the vehicle?

Answer 1

a = u*g = 0.55 * (-9.8) = -5.39 m/s^2.

V^2 = Vo^2 + 2a*d.
Vo^2 = V^2 - 2a*d. = 0 - 2(-5.39)*52 =
561.
Vo = 23.7 m/s.