When a moving object reduces its speed, what happens to the objects acceleration in relation to its velocity?

Atypical jetliner lands at a speed of 146 mi/h and decelerates at the rate of (10.4 mi/h)/s. if the jetliner travels at a constant speed of 146 mi/h for 1.5 s after landing before applying the brakes, what is the total displacement of the jetliner between touchdown on the runway and coming to rest?