As the two masses are connected, the tensions in the string T and the acceleration a are the same.

The smaller mass will be accelerated up with a net force F_{net 2 }= T - m2g. The larger mass will be accelerated down with a net force F_{net1 }= m1g - T. As T is the same for both masses, solve for T and equate the results.

But F_{net 2} = m2a and F_{net1} = m1a

T = m2a + m2g = m1g - m1a

Substituting values and solving for a = 3.6 kg x 9.8m/s^{2} / 9.6 kg = 3.68 m/s^{2}

As the 3.00 kg weight will travel the same distance as m1 but

upward, the velocity can be found by

V = √(0 + 2 x a x 2.60 ) = 4.37 m/s

Please check math.