Conservation of Energy with changing masses on ice

[Nojins]

Homework Statement

Mass 1(75kg) glides on ice at 1.8 m/s to a second stationary mass, (52 kg) How far will the pair slide after the collision if the coefficient of kinetic friction between the ice and their skates is .042?

Homework Equations

Conservation of energy, Kinetic Energy, Work
Ek=1/2mv^2, W=FΔd, Ff=μk(Fn)

The Attempt at a Solution

I understand that all the initial energy (121J) is the moving object's kinetic energy and that the energy is conserved. I'm just confused how I would set up the equation given that the overall mass changes.
The force of friction for the first mass is 31N, and the force of friction for both masses is 52.3. I don't know how to factor this in.
I think this is a nonelastic collision, but please correct me if I'm wrong. Do I use Momentum? P=mΔv

 

[tnich]

Homework Statement

Mass 1(75kg) glides on ice at 1.8 m/s to a second stationary mass, (52 kg) How far will the pair slide after the collision if the coefficient of kinetic friction between the ice and their skates is .042?

Homework Equations

Conservation of energy, Kinetic Energy, Work
Ek=1/2mv^2, W=FΔd, Ff=μk(Fn)

The Attempt at a Solution

I understand that all the initial energy (121J) is the moving object's kinetic energy and that the energy is conserved. I'm just confused how I would set up the equation given that the overall mass changes.
The force of friction for the first mass is 31N, and the force of friction for both masses is 52.3. I don't know how to factor this in.
I think this is a nonelastic collision, but please correct me if I'm wrong. Do I use Momentum? P=mΔv

I think the question is ambiguous, too. Given that it asks how far the pair slides, I think the idea is that the pair of masses merges at the point of collision and they slide together.
Why don't you take a shot a solving it and see what happens?

 

[haruspex]

that the energy is conserved.

I think this is a nonelastic collision

So work is not conserved.