(11%) Problem 3: Three changes are placed on the x-axis. The first has a charge 691μC and is placed at x1 −1.86 m. The second has a charge 531 pC and is placed at x2=5.58 m. The third has a charge 3∗θμC and is placed at x3=8.64 m. Determine the magnitude of the net force on the first charge. F NET=___