Seek: S2

Solution:

S 1=V*t 1/2

S2=V*t2/2

△t=t 1-t2

s = s 1+S2 = V * t 1/2+V *(t 1-△t)/2

1000m = 340m/s * t1/2+340m/s * (t1-0.28s)/2

t 1= 1047.6/340 S

S 1=V*t 1/2=523.8m

S2 = s-s1=1000-523.8m = 476.2m.