The impulse is equal to the variation of momentum of the object:
[tex]I=\Delta p = m \Delta v[/tex]
where m is the mass object and [tex]\Delta v = v_f - v_i[/tex] is the variation of velocity of the object.
The ball starts from rest so its initial velocity is zero: [tex]v_i=0[/tex]. So we can rewrite the formula as
[tex]I=m v_f[/tex]
or
[tex]v_f = \frac{I}{m} [/tex]
and since we know the impulse given to the ball (I=16 Ns) and its mass (m=2 kg), we can find the final velocity of the ball:
[tex]v_f = \frac{16 Ns}{2 kg}= 8 m/s[/tex]
