The immediate cause of many deaths is ventricular fibrillation, an uncoordinated quivering of the heart, as opposed to proper beating. An electric shock to the chest can cause momentary paralysis of the heart muscle, after which the heart will sometimes start organized beating again. A defibrillator is a device that applies a strong electric shock to the chest over a time of a few milliseconds. The device contains a capacitor of a few microfarads, charged to several thousand volts. Electrodes called paddles, about 8 cm across and coated with conducting paste, are held against the chest on both sides of the heart. Their handles are insulated to prevent injury to the operator, who calls Clear! and pushes a button on one paddle to discharge the capacitor through the patient's chest Assume an energy of 3.00 102 W s is to be delivered from a 30.0-F capacitor. To what potential difference must it be charged?

(II) You want to design a portable electric blanket that runson a 1.5-V battery. If you use a 0.50-mm-diameter copperwire as the heating element, how long should the wire be ifyou want to generate 18 W of heating power? What happensif you accidentally connect the blanket to a 9.0-V battery?

80 In Fig. 27-73, R1 = 5.00 0, R2 = 10.0 0, R3= 15.0 n, C= 5.00 µF, |C = 10.0 µF, and the ideal battery R. %3D has emf & = 20.0 V.Assuming that the circuit is in the steady state, what is the total energy stored in the two R1 C2 capacitors?