Block 1, with mass m1 and speed 5.5 m/s, slides along an x axis on a frictionless floor and then

one-dimensional
frictionless-floor

#1

Block 1, with mass m1 and speed 5.5 m/s, slides along an x axis on a frictionless floor and then undergoes a one-dimensional elastic collision with stationary block 2, with mass m2 = 0.34m1. The two blocks then slide into a region where the coefficient of kinetic friction is 0.55; there they stop. How far into that region do (a) block 1 and (b) block 2 slide?

Answer:

I’m confused. The problem states it’s an elastic collision. If both blocks slide after the collision, that sounds like they are sticking together, causing an inelastic collision