I'm stuck on this question. I worked out part a and part b. But I'm stuck on how to approach part c. I attached my work below. Am I supposed to treat the boxes as a projectile.

\fm1 15 m2 h2 Figure 1: A cube with mass m1 slides down a frictionless incline as shown in Fig. 1 and elastically strikes another cube with mass m2 at the bottom. The heights of the incline and the table are h, and h2 respectively. Right before and after the collision, both cubes have the velocity only in the horizontal direction. (a) Find the speed v1 of the first cube right before the collision. (b) Find the speeds v, and v2 of the first and second cubes right after the collision. (c) Find the horizontal distances 1 and x2 that the cubes traveled. U 99+