Earth's lower atmosphere contains negative and positive ions that are produced by radioactive elements in the soil and cosmic rays from space. In a certain region, the atmospheric electric field strength is 99.5 V/m and the field is directed vertically down. This field causes singly charged positive ions, at a density of 661 cm , to drift downward and singly charged negative ions, at a density of 753 cm-3, to drift upward (see the figure). The measured conductivity of the air in that region is 3.16 x 10-14 ((-m) 1. Calculate (a) the magnitude of the current density and (b) the ion drift speed, assumed to be the same for positive and negative ions. + (a) Number i Units (b) Number UnitsThe gure shows wire section 1 of diameter D1 = 6.50R and wire section 2 of diameter D2 = 4.00R, connected by a tapered section. The wire is copper and carries a current. Assume that the current is uniformly distributed across any cross-sectional area through the wire's width. The electric potential change Valong the length l. = 2.50 m shown in section 2 is 15.0 pV. The number of charge carriers per unit volume is 8.10 X 1028 m'3. What is the drift speed of the conduction electrons in section 1? A V Number a Units A student keeps his 9.0 V, 10 W radio turned on at full volume from 5:00 pm. until 2:00 am. How much charge went through it? Number I Units 4} The current through the battery and resistors 1 and 2 in Figure (0) is 1.40 A. Energy is transferred from the current to thermal energy Eth in both resistors. Curves 1 and 2 in Figure (b) give the thermal energy Eth dissipated by resistors 1 and 2, respectively, as a function of time t. The vertical scale is set by Eth,s = 56.0 mJ, and the horizontal scale is set by t5 = 3.10 s.What is the power supplied by the battery? R\" (a) Number I Unit A Y