The mechanical energy of a one kilogram body at rest on the surface of the Earth is -63 million joules. That mechanical energy can easily be converted into kinetic energy. So how fast does a one kilogram body have to travel in order to have a kinetic energy of -63 million joules?
Then again, maybe mechanical energy is a bunch of baloney. Please read my essay The Mechanical Energy Formula Is Backwards on my web page http://www.danielzimmer.com/
>Its velocity must be negative, in other words the object must go in the >opposite direction. No mystery.
A negative number times a negative number is a positive number, so even if velocity is negative, kinetic energy is still positive. What do you say now, Xirtamwq?