A long line of charge with uniform linear charge density λ1λ1 is located on the xx-axis and another long line of charge with uniform linear charge density λ2λ2 is located on the yy-axis with their centers crossing at the origin. In what direction is the electric field at point zz = aa on the positive zz-axis if λ1λ1 and λ2λ2 are positive?

Your physics assignment is to figure out a way to use electricity to launch a small 6.0-cm-long plastic drink stirrer. you decide that you'll charge the little plastic rod by rubbing it with fur, then hold it near a long, charged wire, as shown in figure p23.56 . when you let go, the electric force of the wire on the plastic rod will shoot it away. suppose you can uniformly charge the plastic stirrer to 10 nc and that the linear charge density of the long wire is 1.0 x10-7 c/m. what is the net electric force on the plastic stirrer if the end closest to the wire is 2.0 cm away?