Energy: you can't destroy it, but you can certainly waste it. That's what most motorized vehicles do, including trains. Usually, the energy generated when you stop a moving vehicle is dissipated as heat, and is lost to the atmosphere. With GE's ecomagination we've discovered that you can capture and store that energy, then reuse it - that's how our hybrid systems work.
Watch the above video to see a simple illustration of the physics behind dynamic braking. Keep in mind an object's force is measured in newtons, using the equation force = Mass x Acceleration.Note: If you read this via Email or Feed-reader can't see youtube video click Permalink below to see.