Find the the force the person must exert on the 14.5 kg lawn mower to accelerate it from rest to 1.5m/s in 2.5 seconds?

The required acceleration is

a = (1.5 m/s)/2.5 s = 0.6 m/s62,
and the force is
F = m a

(m is the mass in kg. F will be in Newtons)