3. [6] A large vacuum chamber has parallel metal plates at the top and the bottom, separated by 1.75 meters. The plate at the bottom is at V = 0.0 V. The upper plate is charged to a voltage of VTop. In the vacuum chamber a 6.00 gram plastic bead is charged to +25.0 nC and shot straight up from the bottom plate at a speed of vo. a. If = V top = +2.50 106 V, with what speed must the bead be launched to strike the top plate? b. If Vtop -2.50 106 V, with what speed must the bead be launched to strike the top plate? VTop 0 V 6 g; 25 nC Vo 1.75 m