An electron has a constant acceleration of 3.2 m/s². At a certain instant, its velocity is 9.6 m/s. What is its velocity (a) 2.5 s earlier and (b) 2.5 s later?
a. (a) 2.5 m/s, (b) 16 m/s
b. (a) 16 m/s, (b) 2.5 m/s
c. (a) 0 m/s, (b) 12 m/s
d. (a) 12 m/s, (b) 0 m/s