help with physics please...?

Question

determine the stopping distances for a car with an initial speed of 95 km/h and human reaction time of 1.05, for an acceleration (a) a =-4.0m/s^2 (b) a=-8.0 m/s^2

Answer 1

(95 km/hr)(1000 m/km)(1 hr/3600 s) = 475 m/18 s
Reaction time uses (1.05)(475/18) ≈ 27.708 m
(475 m/18 s)^2/(2*4 m/s) ≈ 87.047 m
(a) 87.047 m + 27.708 m = 114.755 m
(b) (475 m/18 s)^2/(2*8 m/s) ≈ 43.523 m
43.523 m + 27.708 m = 71.232 m

Answer 2

on a dime