Friction force acting on the body = μN= μmg = 1 * 5 kg * 9.8=49 N
So, net force acting on the body,
50 N - friction force =ma
Or, 50 N - 49 N=5a
Or, 1=5a
Or, a=1/5 m/s2
Distance traveled in 3 seconds is s = u t + 1/2 a t² = 0 + 1/2 * 0.2 * 3² = 0.9 m