A body weighing 0.8 kg moves at a speed of 2 m / s and collides with a stationary body weighing 0.6 kg.

A body weighing 0.8 kg moves at a speed of 2 m / s and collides with a stationary body weighing 0.6 kg. After after the collision, they began to move as a whole. Determine the speed of the bodies after interaction.

We use the law of conservation of momentum:
m1 * v1 + m2 * v2 = m1 * V1 + m2 * V2
from the conditions of the problem:
v1 = 2 m / s
v2 = 0
V1 = V2 = V
then:
m1 * v1 = (m1 + m2) * V
0.8 * 2 = (0.8 + 0.6) * V
V = 1.6 / 1.4 = 1.143
V = 1.143 m / s – speed of bodies after interaction