2 balls weighing 2 kg, 1 of which moves at a speed of 0.5 m / s, and the second is at rest. They collide, what

2 balls weighing 2 kg, 1 of which moves at a speed of 0.5 m / s, and the second is at rest. They collide, what is the speed of 2 balls after collision if 1 stopped.

Given: m1 = 2 kg, m2 = 2 kg, v01 = 0.5 m / s, v02 = 0 m / s, v1 = 0 m / s
Find: v2 =?
Decision :
m1 * v01 + m2 * v02 = m1 * v1 + m2 * v2
Substitute the numbers we know:
2 * 0.5 + 2 * 0 = 2 * 0 + 2 * v2
1 + 0 = 0 + 2 * v2
1 = 2 * v2
v2 = 0.5
Answer: v2 = 0.5 m / s