00:01
In this problem, we're asked to calculate the number of drops of water that would be held in a one -liter bottle of water.
00:10
So you can imagine that you've got a container of water here, which has one liter of water in it.
00:18
And that's made up of these little droplets.
00:23
And we don't know how big the droplets are.
00:25
But in order to make progress in an estimate problem like this, we need to come up with some reasonable size for these water droplets.
00:34
So i'm just going to choose to make the math sort of easy.
00:38
I'll just imagine that my water droplets are about one millimeter in diameter, and that seems like a pretty reasonable value.
00:48
And this container over here, of course, is filled with water.
00:52
So i'm trying to figure out how many of those one millimeter droplets essentially would fit inside that one liter container of water.
00:59
So if i further make the assumption that the water droplets are perfectly spherical, i can calculate the volume for a drop of water using the equation for the volume of a sphere, and that would just be four -thirds pi times the radius of the droplet of water cubed.
01:24
In this case, that radius is going to be my one millimeter divided by two...