A uniform electric field is established by connecting the plates of a parallel-plate capacitor to a 12-V battery. The plates are separated by 0.75 cm. A charge is placed in the region with value +6.24 oC. Suppose the charge is released from rest at the positive plate and that it reaches the negative plate with a speed of 3.4 m/s. What is (a) the mass of the charge and (b) its final kinetic energy?