Hello!
We can use the kinematic equation:
[tex]a = \frac{v_f - v_i}{t}[/tex]
a = acceleration (m/s²)
vf = final velocity (45 m/s)
vi = initial velocity (25 m/s)
t = time (5 sec)
Plug in the givens:
[tex]a = \frac{45-25}{5} = \frac{20}{5} = \boxed{4 m/s^2}[/tex]