Solve problems involving the work done when an electric charge is moved in an electric field using 𝑉 = ∆𝑈 𝑞. Magnetic fields

An electron is accelerated from rest through a potential difference in a uniform electric field, as shown in the diagram below. The electron enters region R with kinetic energy 8.5 × 10⁻¹⁸ J and travels horizontally. It then enters a second uniform electric field between two charged plates where it is deflected vertically upward and exits region S. a) Determine the potential difference through which the electron was initially accelerated. b) The electron gains an additional 3.2 × 10⁻¹⁸ J of kinetic energy as it moves through region S. Justify whether the upper plate or the lower plate is positively charged.

A proton is moved through a potential difference of 250 V in a uniform electric field. Identify the physical quantity represented by ∆𝑈 in the equation 𝑉 = ∆𝑈/𝑞, and state its value for this scenario.

A proton is moved through an electric potential difference from 4.5 V to 12.0 V between two plates. Calculate the work done on the proton. Show your working.