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.
Mechanical energy can be divided into two different types of energies. Kinetic energy is the form of energy that causes movements. Potential energy is the form of energy that occurs due to the placement of the object.