A heart defibrillator is used to enable the heart to start beating if it has stopped. This is done by passing a large current of 12.0 A through the body at 25.0 V for a very short time, usually about 3.00 ms.

(a) What power does the defibrillator deliver to the body?
(b) How much energy is transferred?

To solve this problem we will apply the concepts related to Power, such as the product of voltage and current. Likewise, Power is defined as the amount of energy per unit of time, therefore, using this relationship we will solve the second part.

PART A)

We know that Power is,

Substitute for V and 12.0 A for I in the expression,

Therefore the power deliver to the body is 300W

PART B) Converting the time to SI,

Therefore if we have that the expression for energy is,

Here,

E = Energy,

P = Power,

t = Time,

Replacing,

Therefore the energy transferred is equal to 0.9J

c. magnitude and direction