14. A particle accelerator uses electric fields to increase the energy of charged particles. Consider a proton with a mass of 1.67 x 10"- kg that starts at rest and crosses an electric potential difference of 5.3 x 10' V. (a) Calculate the kinetic energy gained by the proton. (b) Calculate the final speed of the proton. (4 marks) 15. A 1.3 x 10" C point charge is moved from 1.4 m to 0.45 m away from a 3.3 x 10" C charged sphere. How much work was required to move the point charge? '(2 marks )