Atransformer is used to convert mechanical energy to electric energy

No it isn't. That's a description of a generator.

Kinetic energy = 1/2mv^2. since the mass is constant we can form a ratio of it's kinetic energy at 60 divided by that at 30 to see ke(60)/ke(30) = +(60^2)/30^2). this may be said to 300% increase.

The magnets would be | n s | and | s n|