13. A student rubs a balloon against her hair. She then places the side of the balloon against a wall and the balloon sticks to the wall. Explain why the balloon sticks to the wall. [2 marks] Part B Communication [10 marks] Communication throughout the test will be evaluated on 1) significant digits (avoid rounding off errors) 2) proper use of units 3) well-labelled diagrams 4) organized, neat and legible 5) Show all work with concluding statements. Level 4 Level 3 Level 2 Level 1 Communicates for different Communicates for different Communicates for different Communicates for different audiences and purposes with a high | audiences and purposes with audiences and purposes with some audiences and purposes with degree of effectiveness considerable effectiveness. effectiveness limited effectiveness Uses conventions, vocabulary, and Uses conventions, vocabulary, and Uses conventions, vocabulary, and Uses conventions, vocabulary, and terminelogy of the discipline with a | terminology of the discipline with terminology of the discipline with terminology of the discipline with high degree of effectiveness considerable effectiveness some effectiveness limited effectiveness Part C Thinking (Full Selution is required) [10 marks] 14. Robert Millikan received a Nobel Prize for determining the charge on the electron. To do this, he setup a potential difference between two horizontal parallel metal plates. He then sprayed drops of oil between the plates and adjusted the potential difference until drops of a certain size remained suspended at rest between the plates. as shown above. Suppose that when the potential difference between the plates is adjusted until the electric field is 1.00 x 10* N/C downward, a certain drop with a mass of 3.27 = 107 kg remains suspended. a. What 1s the charge on this drop? (4 marks) b. If the distance between the plates is 0.010 m, what is the battery's potential? (3 marks) . The oil in the drop slowly evaporates while the drop is being observed. but the charge on the drop remains the same. Indicate whether the drop remains at rest, moves upward, or moves downward. Explain briefly. using equations to support your answer. (3 marks) s are Reguired) [20 marks] 14. An electron 1s released from rest at the negative plate in a parallel plate apparatus kept under vacuum and maintained a potential difference of 5.0 X 10! V. With what speed does the electron collide with the positive plate? (m=9.11x10"kg, q=-1.6x10"C) [2 marks] 15. A 1500-kg satellite 15 moved from an orbit of 2 Earth radii to an orbit of 2.5 Earth radii. How much energy is required to accomplish this? (Me=5.98 x 10 kg, Re = 6.38 x 10 m) (4 marks) 16. Two masses of 5.0 g each are suspended from thin strings and a charge is placed on each. The result is shown in the diagram below. If the angle between each string and the vertical is 157 and the length of the string 15 35 em, determine the charge . (4 marks) 17. Electrons are accelerated through a potential difference, Vo = 120 V, before exiting and being subjected to a new set of parallel plates. The electrons enter this region 5.0 em from the bottom plate, and hit this bottom plate a distance of 5.0 em in. If the total plate separation of this second set of plates 1s 8.0 em, determine the voltage of the second source AND draw this source in, clearly showing the positive vs negative terminals of the battery. (m=9.11 10 kg, q = 1.6x10"C) (10 marks)