An electron initially 3.00 m from a non conducting infinite sheet of uniformly distributed charge is fired toward the sheet. the electron has an initial speed of 410m/s and travels along a line perpendicular to the sheet. when the electron has traveled 2.00 m , its velocity is instantaneously zero, and it then reverses its direction. a- what is the surface charge density on the sheet? b- given the same initial velocity, from what distance should the electron be fired if it is to just reach the sheet?

Two manned satellites approaching one another at a relative speed of 0.550 m/s intend to dock. the first has a mass of 2.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. assume that the positive direction is directed from the second satellite towards the first satellite. (a) calculate the final velocity after docking, in the frame of reference in which the first satellite was originally at rest.(b) what is the loss of kinetic energy in this inelastic collision? (c) repeat both parts, in the frame of reference in which the second satellite was originally at rest. final velocity(d) loss of kinetic energy = ?