v=u+at gives the velocity v after time t, when the initial velocity is u and the acceleration is a. (Negative acceleration is deceleration.)
So v=2.35×10⁵-1.10×10¹²×1.5×10⁻⁷=2.35×10⁵-1.65×10⁵=
(2.35-1.65)×10⁵=0.7×10⁵=7×10⁴.
So the final velocity is 7×10⁴m/s or 70000m/s or 70km/s.