7. [-/2 Points] DETAILS SERPSE10 22.4.OP.014. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) Three point charges are located on the circumference of a circle of radius r, at the angles shown in the figure. 150 230 270 -2q What is the electric field at the center of the circle due to these point charges? (Express your answer in vector form. Use the following as necessary: ke, q, and r.) E= (b) What If? What is the minimum electric field magnitude that could be obtained at the center of the circle by moving one or more of the charges along the circle, with a minimum separation of 8.60 between each of the charges? Express your result as the ratio of this new electric field magnitude to the magnitude of the electric field found in part (a). Eminimum = Epart (a) Need Help? Read It6. [-/4 Points] DETAILS SERPSE10 22.4.OP.012.BIO. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Several species of bacteria, including Geobacter metallireducens, have been shown to "eat" electrons, bypassing the usual process of metabolizing sugar to obtain energy. During this process, the bacteria, which already have negatively charged cell membranes, acquire an even larger net negative charge, typically between 10.0e and 85.0e in magnitude. Individual Geobacter are typically 4.00 um in diameter. What are the magnitude and the direction of the electric field of a bacterium with a net negative charge of magnitude 15.0e at a distance of 1.00 mm from the microbe? (a) the magnitude (in N/C) |N/C (b) the direction O radially outward O radially inward What are the magnitude and the direction of the electric force on a second bacterium of net negative charge 30.0e a distance of 1.00 mm from the first bacterium? (c) the magnitude (in N) N (d) the direction O away from the first bacterium O towards the first bacterium Need Help? Read It