1. The problem statement, all variables and given/known data Two parallel metal plates 5.0 cm apart have a potential difference between them of 75 V. The electric force on a positive charge of 3.2*10^-19 C at a point midway between the plates is approximately a. 1.6*10^-18 N b. 2.4*10^-17 - c. 4.8*10^-18 d. 4.8*10^-16 e. 9.6*10^-17 2. Relevant equations V = E*d = (F/q)*d 3. The attempt at a solution F = (V*q)/d = (75 V)*(3.2*10-19 C)/(0.025 m) = 9.6*10^-16 N??? But this does not match any of the choices . . .except for being close to E. Is my arithmetic wrong or is the question in need of editing? 1. The problem statement, all variables and given/known data The electric potential in a region of space is given by V(x,y,z)=10 (V/m)x +20 V/m(y) + 30(V/m)z. The z-component of the electric field in this region is a. (-30 V/m)*k vector b. (-10 V/m)*i vector c. (20 V/m)*j vector d. (-20 V/m)*j vector e. (30 V/m)*k vector 2. Relevant equations See below. 3. The attempt at a solution Is the answer e. (30 V/m)*k vector since V/m = N/C (both units for electric field)? 1. The problem statement, all variables and given/known data When 5.0 C of charge moves at constant speed along a path between two points differing in potential by 12 V, the amount of work done by the electric field is a.2.4 J b. 0.42 J c. 5.0 J d. 12 J e. 60 J 2. Relevant equations U = q*V ?? (correct formula?) 3. The attempt at a solution U = 5.0 C*12V = 60 J? Thanks.