Always use your name for store id. It's most convenient. whenever you have some problems with product, they will ask you for id. So, its better to use real name. I often use some fictitious characters like Peter Parker, Ken Adams, etcetera while signing up on some timepass websites.
The gravitational potential energy near a planet is then negative, since gravity does positive work as the mass approaches. This negative potential is indicative of a bound state; once a mass is near a large body, it is trapped until something can provide enough energy to allow it to escape.
Internal energy is the sum of all microscopic forms of energy of a system. It is the energy needed to create the system. It is related to the potential energy, e.g., molecular structure, crystal structure, and other geometric aspects, as well as the motion of the particles, in form of kinetic energy.