Please I need the steps and explanation

physics 3u NONN 7. A positively charged plate is parallel to a negatively charged plate. The plates are 4.5 cm from each other, a there is a charge of 120 V across the plates. A positively charged particle is between the plates, 1.0 cm from the negative plate. What is the potential difference at the point of the charged particle? (3 marks) 8. In a fictitious universe, gravity varies inversely with distance, not inversely with the square of the distance. Thus, the units of the gravitational constant, G, are Nm/kg rather than Nm/kg2. Compare the weight of a 75.0 kg person on Earth with the weight of the same person in this fictitious universe. (Me = 5.99 x 1024 kg and re = 6.40 x 10' m)