We've all been to the doctor at one point in our lives, and we've all had our blood pressure taken. There's that word again: pressure. How is blood pressure related to the pressure we've been studying in physics?

When the doctor says he needs to check blood pressure, he actually does mean a type of pressure in terms of force. Blood pressure is still determined by force over area, just like any old pressure. In this case, a doctor measures the force applied by blood to the artery walls. Where does this force come from? From the flow of blood pumping through your body. Ooh, that's a powerful idea.

That's why blood pressure is strongly related to the health of a person's heart since the heart is the muscle doing all the work. A high blood pressure indicates a person's arteries and heart are under pressure, literally. This doesn't sound healthy because it's not. It's usually the result of eating junk food, not exercising, or a genetic condition.

So Mom has a point after all with her whole "don't spend all day on the internet" thing.