Question

Who can do this :) gets cake!!

Consider a small disk that can slide on a horizontal plane (covered by xy coordinates) without friction. You launch the disk from the origin of your coordinate system, it eventually hits a wall, bounces off perfectly elastically and crosses the y-axis again at y=1 m.

If the shape of the wall is given by y=x−2, then at what angle with respect to the x-axis in radians did you launch the disk?

*Your answer should be negative as its fired below the x axis*

Reward: Medal + Fan + Testimony + 100000000 DOLLA