A car kinematics problem

[miamiheat5]

Suppose a car traveling at 12.0m/s sees a traffic light turn red. After 0.510s have elapsed, the driver applies the brakes, and the car decelerates at 6.20m/s^2. What is the stopping distance of the car, as measured from the point where the driver first notices the red light?

Homework Equations

d=vt
vf^2=vi^2+2ad

The Attempt at a Solution

d before breaking
d=vt
=12(0.51)
d=6.12m

d after breaking

vf^2=vi^2+2ad
0^2=12^2+2(-6.20)d
-144=2(-6.20)d
d=11.6m

 

[giggidygigg]

seems like you got it right.

 

[robbondo]

looks right to me