Mass, \(m=3\,kg\)

Momentum, \(P = mv\)

Velocity, \(v =\frac{ P }{ m }=\frac{2}{3}\,ms ^{-1}\)

Kinetic energy, \(\frac{1}{2}\,mv ^2=\frac{1}{2} \times 3 \times\left(\frac{2}{3}\right)^2=\frac{2}{3}\,J\)

Hence, kinetic energy is \(\frac{2}{3}\,J\)