Answer:Expression given below
Explanation:
Given mass of spring[tex]\left ( m_1\right )=0.5 kg[/tex]
Compression in the spring[tex]\left ( x\right )=20 cm[/tex]
Let the spring constant be K
Using Energy conservation
potential energy stored in spring =Kinetic energy of Block[tex]\left ( m_1\right )[/tex]
[tex]\frac{1}{2}Kx^2=\frac{1}{2}m_1v^2[/tex]
[tex]v=x\sqrt{\frac{k}{m_1}}[/tex]
now conserving momentum
[tex]m_1v=\left ( m_1+m_2\right )v_0[/tex]
[tex]v_0=\frac{m_1}{m_1+m_2}v[/tex]
where [tex]v_0[/tex] is the final velocity