62 m/s^2
First, convert 155 km/h to m/s
155 km/h * 1000 m/km / 60 min/h / 60 s/h = 43.05556 m/s
Now take the speed in m/s and divide by the number of seconds it took to accelerate it to that speed.
43.05556 m/s / 0.70 s = 61.5 m/s^2
Since we only have 2 significant figures, round the result to 2 figures.
61.5 m/s^2 = 62 m/s^2
