Three charges lie along the x-axis. One positive charge, q1 = 4.80*10^-18 C, is at x = 3.24 m, and another positive charge, q2 = 1.60*10^-19 C, is at the origin. At what point on the x-axis must a negative charge, q3, be placed so that the resultant force on it is zero?

2) a cubical block of stone is lowered at a steady rate into the ocean by a crane, always keeping the top and bottom faces horizontal. which one of the following graphs best describes the buoyant force b on this block as a function of time t if the block just enters the water at time t = 0 s?