Yes, we can calculate the velocity of the body using the equation of motion:
v = u + at
Where: v is the final velocity u is the initial velocity (in this case, it starts from rest, so u = 0) a is the acceleration t is the time
Plugging in the values: u = 0 m/s a = 12 m/s^2 t = 5 s
v = 0 + (12 m/s^2)(5 s) v = 60 m/s
Therefore, the velocity of the body after 5 seconds of acceleration is 60 m/s.