I need help on another Basic Physics problem?

Question

Determine the stopping distances for an automobile with an initial speed of 93 km/h and human reaction time of 2.0 s for the following accelerations.

(a) a = -4.0 m/s2

__________m

(b) a = -8.0 m/s2

___________m

I used the eq d=Vot+1/2att

I tried the following answers but they don't work. I think it is a sig fig problem.

a) 44, 43.7, 44.0, -44

B) -67.7, -68, 67.7, 68

I only have one last change to enter another answer.

Answer 1

ok well im not sure but...

use ..a=s/t to find the time it took to stop...

so..u should get around 23( its rounded)... then use d=Vot+1/2att

=> d=93*2+1/2(4)(23)

u do the math but i did it quickly in my head and got around 232