A1200kg car moving at 25m/s has the brakes applied with a deceeration of 8.0m/s^2. how far does the car travel before it stops?

V=vnaut+at 0(want it to stop)=25+-8t(negative accel cuz its deceling)
-25/-8=t t=3.125 seconds or with sig figs 3.1 seconds
x=xnaut+vnaut*time+1/2*a*time^2
x(where it ends up)=0(we start distance from when it started to brake)+25*3.1+1/2*-8*3.1^2=39.06 meters or 39.1 meters 
x=0+25*3.1-.5*8*3.1^2 is the same equation as above with nothing written in. Are you in physics ap or reg? either way friend me lol(just joined website tonight)

The masses of the objects and their densities