The acceleration from 25 km/h to 30 km/h is greater.
Work Step by Step
The change in velocity for the first case, 30 km/h - 25 km/h = 5 km/h, is greater than for the second case, 100 km/h - 96 km/h = 4 km/h. The elapsed times are the same, so the larger change in velocity results in the greater acceleration. The relevant equation and concepts are discussed on pages 43-44.