Final answer:
The charge of the particles impacting the positively charged plate would be positive. The variation in impact points is likely due to a mass difference, implying the second particle is heavier. This scenario is analogous to gravitational projectile motion with two objects of different masses when air resistance is negligible.
Step-by-step explanation:
The charge of the particles that impact the positively charged plate is positive, since like charges repel each other. To have one particle impact four times as far from the launch point as the other, despite having the same charge and being launched with the same velocity, points to a difference in mass. If the second particle travels four times the distance, this implies it is heavier or less affected by the electric field, causing it to respond less to the field's force. In terms of projectile motion under gravity, this scenario is similar to shooting two balls with the same initial velocity where one ball has a mass four times greater than the other. The heavier ball would travel four times the distance before hitting the ground if air resistance is negligible because the gravitational force on both balls would be the same (assuming they were launched from the same location). In the case of charged particles in an electric field, the force depends on both the particle's charge and the electric field strength. However, assuming the same charge, the mass difference would account for the variation in impact points.