According to a simplified model of a mammalian heart, at each pulse approximately 20 g of blood is accelerated from 0.25 m/s to 0.35 m/s during a period of 0.10 s. What is the magnitude of the force exerted by the heart muscle?

VIDEO TRANSCRIPT

This is Giancoli Answers with Mr. Dychko. The force exerted by the heart will be the net force because it's the only force involved here. And so, we can calculate it by multiplying mass times acceleration. So, we have to do a bit of work to figure out what the acceleration is by taking the change in velocity divided by the time. And so, that's 0.35 m/s minus 0.25 divided by 0.1 seconds. And that gives 1.0 m/s squared is the acceleration in the blood. And then 20 grams converted into kilograms by multiplying by 1 kilogram for every 1,000 grams makes it 0.2 kilograms. And then that makes ma 0.02 kilograms times 1 m/s squared equal to 0.2 Newtons of force exerted by the heart.