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 A through the body at 25 V for a very short time, usually about 3.0 ms. (b) how much energy is transferred?

Video transcript

Hey everyone in this problem, we're told that batteries store energy that is used in diverse ways. The starter motor in a four cylinder engine draws 130 amps at 12 volts. If the starting process lasts 2.5 seconds, were asked to determine the energy supplied. Now we're looking for energy and let's recall that the energy is equal to the power times of time. T. Now we're given the time T. But were not given the power P. However, recall that we can write the power P as the voltage B times the current. And so we get that the energy is equal to V. I. T. Now we're given a value of V. Were given a value of current I and were given a value of T. So we have everything we need. This is simple. We just need to plug those values into our equation and solve. And so we get V. We're told is 12 volts. The voltage, The current I were told is 130 amps. And the time T. We're told is 2.5 seconds. And if we multiply all these, we're gonna have volts times amps, times seconds. This gives us 3900 and the unit is Jules. And so if we look at our answer choices, we see that we have answer a 3900 Jules. Is the energy supplied during this starting process. That's it for this one. Thanks everyone for watching. See you in the next video