How many times does a human heart beat during a person's lifetime? How many gallons of blood does it pump?

Video transcript

Hey everyone. So today we're being told, an electric electrical stimulus is being generated by a small mass of specialized tissue, the sinus node in the heart. Now, we're told That it generates an electrical stimulus of million volts in a person's lifetime. The number or the number of times the average person generates set electrical stimulus in their heart And it's equivalent voltage is 82 times first minute and a life expectancy of 72.6 years respectively. So based on this information, we need to find both the electrical stimulus, the total number of electrical stimuli through the years, as well as the number of volts in a lifetime, which is the second quantity here. So let's start with the electrical stimulus in the lifetime. We have to do some conversions. So we're told that there's 82 times per minute throughout the life for a average life expectancy of 72.6 years. So we need to take 82 times per minute and convert that per minute to per year and figure out how much that is. So let's go ahead and do that. We start off with 82. Ah I'm going to put E. S. For electrical stimuli minute. Now we have to use conversion factors. And these are pretty simple. Once you get the hang of them, let's walk through them for now. We have 60 minutes per hour. Right? one Hour has 60 minutes within it. And we've arranged it as such because this allows us when we multiply for our units are minutes to cancel out. So let's try this again. Going to a bigger denomination. So within one day, let's say just 24 hours within one day again. Because I've written it like this. No one will multiply. Our hours will cancel out. Once again we can go excuse me, we can go to an even higher denominator. So since we now need to get two years since our life expectancy is in years. Well we can use a conversion factor because we know we have days within one year, one year. And our units will again cancel out. Finally, Our last thing that we need is our 72.6 years, our life expectancy because that will allow the years to also cancel out. And now we multiply all the values because the bottoms are all one. So we multiply 82 times 60 times 24 times 3, 65 times 72.6. And we get an answer of 3.129 . Times 10 to the 9th, 10 to the 9th. Yes per lifetime. So that is the first half. So with that information, we can actually rule out answer choice B because that does not have the correct lifetime electrical stimulus. With this electrical stimulus in hand though, we can go ahead and also figure out the number of volts that happened within a lifetime Because we're given that the electrical stimulus is 60 mil levels. So if we have ah three times or 3.129 we have, let's write this in blue. We have 3.129 times 10 to the 10 to the ninth. Sorry, not negative electrical stimuli in our lifetime. And As given here we have 60 million volts per every electrical stimulus. But we want our answer and volts remember. So we have to do one more conversion factor. So we take and let's write this one in green. We take 60 million volts per electrical stimulus. And we know that for every one volt There are 1000 milli volts and simplifying all this. Our electrical stimuli will cancel, our millie volt will cancel and we'll be left with a final answer of 1.8774 times 10 to the 8th volts per lifetime. So with these values in hand we can go ahead and say that answer. Choice D is our correct answer. I hope this helps. And I look forward to seeing you all in the next one.