Answer to Question #301502 in Electricity and Magnetism for Hutchii

Question

A particle charge 4 x 10 ^-9 C is located at a point (0,0) in a certain coordinate system. Assuming all lengths are in meters, calculate the potential of the following points: A (3,3) and B (0,2). How much work is needed to take a particle of charge 2 x 10^-5 C from A to B?

Answer 1

$\varphi_A=\frac{kq_1}{r_A}=6.9~V,$

$\varphi_B=\frac{kq_1}{r_B}=18~V,$

$A=q_2(\varphi_B-\varphi_A)=0.22~mJ.$