What is the net electric potential at the origin due to the circular arc of charge Q1 = +7.21 pC and the two particles of charges Q2 = 4.00Q1 and Q3 = –2.00Q1? The arc’s center of curvature is at the origin and its radius is R = 2.00 m;

Ithink your answer is d

Gotta have a picture ^^

Ke reqd to move from 0 to 50 will be proportional to 50x50 or 2500. this is equal to w.  to change vel from 50 to 150 you need energy prop to 22500 - 2500 = 20,000. this corresponds to 8w.  best answer is a) . work reqd is prop to velocity squared.