shows a 4.0cm-wide plastic film being wrapped onto a 2.0cm-diameter roller that turns at 88rpm. The plastic has a uniform surface charge density of 1.5nC/cm2. What is the current of the moving film? Express your answer to two significant figures and include the appropriate units. How long does it take the roller to accumulate a charge of 10C ? Express your answer to two significant figures and include the appropriate units. Variations in the resistivity of blood can give valuable clues about changes in various properties of the blood. Suppose a medical device attaches two electrodes into a 1.3-mm-diameter vein at positions 4.8cm apart. Part A What is the blood resistivity if a 9.0V potential difterence causes a 230A current through the blood in the vein? Express your answer in ohm-meters. The electron dritt speed is 1.5104m/s in a metal with a mean free time between collisions of 5.61014s. Part A What is the electric field strength? Express your answer to two significant figures and include the appropriate units. A circuit calls for a 0.600mm-diameter copper wire to be stretched between two points. You dont have any copper wire, but you do have aluminum wire in a wide variety of diameters. Part A What diameter aluminum wire will provide the same resistance? Express your answer with the appropriate units