Physics 30: Assignment 4 12 7. A battery is attached to two parallel metal plates. The plates are separated by 5.00 mm and produce an electric field of 600 V/m. Determine the electric field strength if the plates are moved to a separation distance of 3.00 mm. (1 mark) 8. A proton gains 1.76 x 10-15 J of kinetic energy as it passes through an electric field. Calculate the potential difference causing its acceleration. (2 marks) 9. a) Determine the maximum speed an alpha particle could obtain if it moves from rest through a potential difference of 8.40 kV. Hint: see workbook p. 107 (2 marks) b) State the physics principle you used to solve this question (1 mark)