please somebody :(

A 20-kg block, initially moving 12 m/s, slides 5 meters across a rough horizontal surface from point A to point B, producing 400 J of thermal energy. It then slides along a frictionless surface from point B up the ramp to point C.
Find the speed of the block at the top of the ramp (point C). Show your work.

the height of C is required for a solution

the height of C is 3 meters