The electric potential energy of an electron increases when it is moved away from a positive
Its speed will lessen.
Energies of some atomic and molecular processes
Breaking a hydrogen bond between two water molecules: 0.24 eV
Energy released in metabolizing one molecular of ATP: 0.32 eV
Breaking the bond between atoms in a water molecule: 4.7 eV
Ionizing a hydrogen atom: 13.6 eV
Q = C ΔV C
Charge on a capacitor with potential difference ΔC
Unit: farad, F
1 farad = 1 F = 1 C/V
C = d
Capacitance of a parallel-plate capacitor with plate area A, separation d
1 Q 2 1
U C = C (ΔV C2
2 C 2
Electric potential energy of a capacitor with charge Q and potential difference
The flash unit in a camera creates a very short but very bright flash: 10 W for a time of 10 μs.
The flash is produced by a 22 μG capacitor.
To what voltage must the capacitor be charged?
ΔE = PΔt
ΔE = (100,000 W) (10 x 10 sec)
ΔE = 1.0 J 1.0 J = ½ (22 x 10 F) (ΔV) 2
V = 300 volts
The positive nuclei shift very slightly in the direction of the field.
The negative electrons shift very slightly in the direction opposite to the field.
Because of polarization, one surface has an excess of positive charge and the other has
an excess of negative charge.
κ ϵ A
C = d
Capacitance of a parallel-plate capacitor with a dielectric of dielectric constant κ
The net electric field is the vector sum of the applied field and