What is volume flow rate? (article) | Fluids | Khan Academy
Australia inherited this system at the time of European settlement Knowledge of relationships between units Chooses appropriate units of measurement for length, area, volume, The word perimeter means 'a path that surrounds an area '. The word Physics originates from the Greek word Physis, which means nature. Definition: "MEASUREMENT" is the determination of the size/magnitude of something. 2 Length, Mass and Time; 3 Dimensional and Unit Analysis; 4 Density. You might hear the term volume flow rate and think it sounds boring, but volume flow rate keeps you alive. I'll tell you how in a second, but first we should define.
So all of a sudden at this point-- I'm going to just kind of erase it-- you don't allow any more contraction, so you wouldn't have this sharp increase in pressure.
In fact, you wouldn't have any of this, right? If I could actually vacuum up all the calcium, you wouldn't have any of that systole really happening.
You'd be basically kind of stuck in diastole. So you'd basically be stuck here, right?
And this is-- remember this point we used to call end diastolic. So when you get to that end diastolic point, instead you'd be basically kind of stuck in limbo, right? Now, what if I took it one step further, and I said, well-- I'm just going to make a little space here by erasing all of this-- what if I now draw for you the heart?
What is volume flow rate?
Let's draw the left ventricle out like that. And I'm not going to draw the left atrium, just the left ventricle. And I'm going to fill it in to look something like this, right? So you've got lots of blood inside of that chamber of the heart, right? It's full of blood. And let's say, now that it's full of blood and it's not contracting, I've got to do something with the left ventricle, and I decide to kind of continue my experiment.
And I say, OK, I'm going to take an injection, and I'm going to inject this left ventricle full of blood. I'm going to put more blood into the left ventricle.
I'm going to put more blood in. You might be thinking, well, how in the world do you put more blood into something that is full? If it's full, it's full, right? So how can you put more blood in? Well, think of it like a balloon. You can have a full balloon, but if you put enough pressure, you can actually increase the volume, right?
So in this case, it will take pressure.
And you know I'm not going to candy coat this, this will take work. But if you're willing to do it, you could actually put more blood into a full ventricle. So let's extend this out. Let's say I put some extra volume in, right, like that.
Well, my pressure will go up a little bit, and my curve will look like this. Let's say I extend this out, it'll start looking like that. And I could actually do it again. I could put more volume in there.
- Fundamentals of Physics/Physics and Measurement
- End diastolic pressure-volume relationship (EDPVR)
And this time it took, actually, a little bit more effort because it's getting harder and harder, not unlike a balloon, right-- looking like that. And I could do it again. I could say, well, let me try one more time. And now it's getting even harder, right-- even harder to do this.
So my curve is kind of looking a little bit more like this, more steep as time goes on. So on the one hand, I'm adding more volume. That's what all these v's are. But as I do that, the pressure's going up. That's what these p's are. So pressure and volume are, of course, related, right? And we could do the reverse. I could actually flip it around, and say, well, hold on a second. Instead of adding blood, what if I decide to take blood away?
What if I want to do something like this where I actually pull blood away off of the heart, suck it back, and take it, and maybe throw it down the sink? Then what would happen? Well, let's say I start at the same end diastolic point, just to kind of make it nice and clear.
Well, if I was to do that, if I was to take blood away, then my volume, of course, would go down. And if the volume goes down, the pressure goes down.
I could take more volume way, and the pressure would go down. And actually, it would look pretty much the same as that chunk of our pressure volume loop.
So you can actually see now, when we have our pressure volume loop, that's actually kind of showing you what it would look like to fill up the heart. And it makes perfect sense, right?
As you change the volume, of course the pressure will fall a little bit. If you take more volume away, the pressure will fall even more. But what if I kept doing it?
The Relationship Between Mass, Volume & Density | Sciencing
What if I just kept extending this out and taking more volume off? Well, the pressure would go down a little bit. I could take even more volume off, and I could end up with really no blood in my chamber. And I would have, of course, no pressure at that point.
Boyle's law - Wikipedia
So you can actually connect these lines. You could say, OK, well, this is kind of what the curve might look like, right-- something like that. And of course, I would have to erase this little chunk because that was not related to passive filling, right? That was, remember, where the left ventricle was still relaxing. And I could also just erase all this stuff to make our line more clear and easy to see. And so now what you see emerging is a fantastic relationship, right-- a pressure-volume relationship.
And this pressure-volume relationship is assuming that the left ventricle muscles are relaxed, right? While that cannot apply in all situations, these factors may be used in some limited scopes. Estimates and Order-of-Magnitude calculation[ edit ] The order of magnitude gives the approximate idea of the powers of Significant Figures[ edit ] A significant figure is a digit within a number that is expected to be accurate.
In contrast, a doubtful figure is a digit that might not be correct. Significant figures are relevant in measured numbers, general estimates or rounded numbers. As a general rule, any non-zero digit shown is a significant figure. Zeros that appear after the decimal point and are at the end of the number are also significant.
Zeros at the end of the number but before the decimal point are not included as significant figures although exceptions may occur. In general, an operation performed on two numbers will result in a new number. This new number should have the same number of significant digits as the least accurate number. If an exact number is used, it should have the same number of digits as the estimated number.