A mass with a velocity has a Kinetic Energy.
We can build a story of an Inclined Plane with Conservation of Energy. We simplify the tale by making the surface frictionless and eliminating wind resistance. The sled has Potential Energy and as it slides down the plane, Potential Energy converts to Kinetic Energy. At the bottom of the slide, there is no more Potential Energy–all the potential energy has converted to kinetic energy.
Vectoreverything 