A tiny ball (mass = 0.015 kg) carries a charge of -17 pC. What is the electric field magnitude that would cause the ball to float above the ground? Number i 9.2E+3 Units N/CReview Conceptual Example 11 before attempting to work this problem. Four charges with equal magnitudes of 7.03 x 10 12C are placed at the corners of a rectangle. The lengths of the sides of the rectangles are 3.83 cm and 7.03 cm. Find the magnitude of the electric field at the center of the rectangle in Figures a and b. +4 +4 +4 (a) (b) (a) Number 7.9E+1 Units N/C (b) Number 79 Units N/CTwo charges are located on the x axis: q1 = +8.4 /C at x1 = +4.9 cm, and q2 = +8.4 p/Catx2 = -4.9 cm. Two other charges are located on the y axis: q; = +3.7 pC at y; = +4.8 cm, and q4 = -9.8 JC at y4 =+7.1 cm. Find (a) the magnitude and (b) the direction of the net electric field at the origin. 43 42 (a) Number 3.1E+6 Units N/C (b) The net electric field points along the ty direction