"an empty cylindrical barrel is open at one end and rolls without slipping straight down a hill. the barrel has a mass of 19.0 kg,19.0 kg, a radius of 0.260 m,0.260 m, and a length of 0.650 m.0.650 m. the mass of the end of the barrel equals a fifth of the mass of its side, and the thickness of the barrel is negligible. the acceleration due to gravity is

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.