Question

A gas contains two types of particles. Particle A has mass m and velocity vo in the +z-direction. It collides head-on with particle B that has mass 5m and velocity 2vo in the -z-direction Electrostatic force then holds the particles together. What is the final velocity of the two-particle system?

Answer 1

AAAaannndd the bot gets it wrong yet again!
The initial momentum is not zero

conserve momentum, so
m*v0 - 5m(2v0) = (m+5m)v
v = -3/2 v0

Answer 2

The final velocity of the two-particle system is zero, since the particles collide head-on and the electrostatic force holds them together. The momentum of the two-particle system is conserved, so the total momentum of the system before the collision is equal to the total momentum of the system after the collision. Since the particles have opposite velocities, the total momentum of the system before the collision is zero, and the total momentum of the system after the collision is also zero. Therefore, the final velocity of the two-particle system is zero.