Class Notes (806,815)
United States (312,228)
Physics (56)
PH 122 (46)

Capacitor formulas, dielectrics, electric field of the cell membrane

3 Pages
Unlock Document

Colorado State University
PH 122
Brian Jones

7 February The electric potential energy of an electron increases when it is moved away from a positive charge. 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 Capacitor Formulas Q = C ΔV C Charge on a capacitor with potential difference ΔC Unit: farad, F 1 farad = 1 F = 1 C/V ϵ A 0 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 ΔV C 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 -6 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 Dielectrics 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 0 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
More Less

Related notes for PH 122

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.