Therefore , m_1 v_2=(m_1+m_2 )v
or 4 X 6 + 2 X 0 = 6v
which gives v = 4 m/s
Hence, the system now consists of a total mass of 6 kg having kinetic energy,
K=1/2 mv^2=1/2 x6x16=48J
Potential energy of the system isU=1/2 kx^2 x1.97x〖10〗^5 x(-0.01)^2≈10J
Thus the system now has a total mechanical energy of E = K + U = 58 J
When the blocks come to rest at their new extreme position (say X) after the collision, all this energy should be equal to the potential energy of the spring ,1/2 kx^2=58J.
which gives X = 0.024 m = 2.4 cm