A) determine the numerical value for the particles speed, just as it reaches the right plate

Problems 4. [7 points] The diagram below shows a charged particle - either a proton or an electron that is moving to the right between two parallel charged plates. The plates are separated a by a distance d = 2.00 mm = 2.00 x 10- m; the left plate has a potential Vi = -70.0 the V and the right plate has a potential V2 = -50.0 V. The particle is slowing down from an initial speed of v; = 90.0 x 103 m/s at the left plate. The mass of a proton is my = 1.67 x 10-2 kg, the mass of an electron is me = 9.11 x 10- kg, the charge of a proton is qp = +1.60 x 10-19 C, and the charge of an electron is ge = -1.60 x 10-19 C. 5