Physics problem

[Andrez]

Indeed the slope is taken into account, but I meant that I thought mgh was only to be used in case of a freefalling object. I guess a freefall and sliding down through a slope must be the same thing in a mathematical context (considering both with no friction), and slope just changes the fact that instead of a block "sunk" into terrain (along y-axis), we'll have a mass with kinetic energy that goes on along the x-axis.