Answer: I showed you all calculation . You did not attach any graph to question .
Step-by-step explanation:
Lets first find Velocity
Vr=o m/s
Ve=?
a=1m/s²
t=2s
----------
a=(Vr-V)/t
1m/s²=Vr-0m/s/2s
2m/s=Vr
Lets find the time neeeded to stop :
a=1m/s²
Vs=2m/s
Vf=0m/s
a=(Vf-Vs)/t
t*1m/s²=2m/s
t=2 s