F = 6N, m = 2kg, t = 4s, u = 0 (stationary or at rest)

K.E
=
1
2
mv\(^2\)

F
=
mv
t
from rest
K.E
=
1
2
m(
Ft
m
)\(^2\)
=
1
2
×
2 x (\(\frac{6 \times 4}{2})^2 = 12^2 = 144J\)