Question

The electrical signals to the heart are typically coordinated to create a wave of compression that travels across the heart and pumps the blood through the heart chambers. If these signals get misaligned, the bits of the heart muscle vibrate independently and as a result do not move blood. This situation is called fibrillation and can quickly lead to death. If the situation is caught in time, passing a jolt of current through the heart can realign the electrical signals in the heart and start it beating again. The device that delivers this current is a defibrillator. The central component of a defibrillator is a big capacitor A battery takes perhaps half a minute to charge this capacitor. A typical defibrillator capacitor might have a capacitance of s2 F and is charged by a battery to a potential difference of 4210 V, 1. What in the magnitude of charge stored on one of the capacitor plates when it is fully charged? 101 MC 2. The energy stored in a capacitor is MIQUAM. How much energy (electric potential energy in this case) is stored in the defibrillator's capacitor when it's fully charged? The energy in the capacitor is delivered by placing paddles on either side of the victim's heart as shown in the figure. The defibrillator delivers the charge stored in the capacitor through the paddles, hopefully resetting the heart so it can begin beating normally

Answer 1

(1)

Q= C del V = 52* 10^-6(4210) = 218920 uC

(2)

Ue = Q del V/2 = 0.21892 (4210)/2 = 460.8266 J

(3)

I = Q/t = 0.21892/100* 10^-3 = 2.1892 A

(4)

P = Ue/t =  460.8266 J/100* 10^-3 = 4608.266 W

(5)

del V = P/I = 4608.266 W/2.1892 = 2105 V

(6)

Reff = V/I = 2105/2.1892 = 961.53 ohm