In the figure a charged particle (either an electron or a proton) is moving rightward between two parallel charged plates separated by distance d = 7.60 mm. The plate potentials are V1 = −63.0 V and V2 = −51.0 V. The particle is slowing from an initial speed of 83.0 km/s at the left plate. (a) Is the particle an electron or a proton? (b) What is its speed just as it reaches plate 2?