Question

a) Find the potential energy at the midpoint from a line that joins charge -15 x10^-6C with a charge +13 x10^-6C that is located 0.08m from first charge.

b) A charge +55 x10^-9C is 0.08m at left of a charge -16 x10^-9C. Find the potential at a point located 400cm left from charge q=16 x10^-9C.

Answer 1

a)

$$E=-(9\cdot10^{9})\frac{(15\cdot10^{-6})(13\cdot10^{-6})}{0.08}=-22\ J$$

b)

$$V=(9\cdot10^{9})\frac{(55\cdot10^{-6}-16\cdot10^{-6})}{0.04}=8.8\cdot10^{6}\ V$$