Question

A point charge `q_1=+2.40muC` is held stationary at the origin. A second point charge `q_2=-4.30muC` moves from the point x=0.150 m, y=0 to the point x=0 0.250 m, y=0.250 m. How much work is done by the electric force on `q_2`?

Answer 1

Correct Answer - C
`W=-/_U=U_i-U_f=q_2V_i-q_2V_f`
`=q_2((kq_1)/r_1)-q_2((kq_1)/r_f)`
`=kq_1q_2(1/r_i-1/r_f)`
`=(9xx10^9)(2.4xx10^-6)(-4.3xx10^6)`
`(1/0.15-1/(0.25sqrt2))`
`=-0.356J`