A ball weighing 2 kg moves at a speed of 3 meters per second and collides with a ball weighing 1 kg, which moves towards

A ball weighing 2 kg moves at a speed of 3 meters per second and collides with a ball weighing 1 kg, which moves towards it at a speed of 4 meters per second. Determine the speed of the balls after a direct inelastic impact.

Given: m1 = 2kg, v1 = 3 m / s, m2 = 1kg, v2 = 4 m / s, non-elastic impact, towards
Find: v =?
Decision :
The law of conservation of momentum in the case of an inelastic counter-impact:
m1v1 – m2v2 = v * (m1 + m2)
Substitute the known numbers:
2 * 3 – 1 * 4 = v * (2 + 1)
6 – 4 = v * 3
2 = 3v
v = 2/3
v = 0.67
Answer: 0.67 m / s