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# Particle collisions

## Problem

Two particles are travelling horizontally towards each other. Particle A has a velocity of 5 units in the x direction. Particle B has a velocity of minus, 3 units in the x direction.
Assuming the mass of the particles is the same and the collision is completely elastic, after the particles have collided,
What is the velocity of particle A in the x-direction?
units.
What is the velocity of particle B in the x-direction?
units.
Stuck?
Stuck?