00:01
Here are the four cells given to calculate their surface area, which is the sa, and then the volume.
00:13
So i'd like to take you through with a little bit of formulas in detail just in case you have questions.
00:23
So surface area for a sphere is 4 pi r, so the radius is 6, so altogether you get 452.
00:35
Here is a formula for the volume, again straightforward calculation.
00:42
For the rectangle, their surface areas, they are three different shapes.
00:51
And therefore the first one is going to be two of them, and each one is 4 by 5.
01:01
The second one is this one, 5 by 5, but there are two of them.
01:09
The last one is 4 by 5 again here, and there are two of them.
01:16
So altogether the surface area is 130.
01:20
The volume is multiplied by all three numbers, that gives you 100.
01:26
The cylinder, the surface areas are the two round circles in the cylinder itself, so the 2 pi r squared accounted for those two, whereas 2 pi r h, h equals to 6, is the cylinder body.
01:50
So that's 251.
01:52
The volume wise is pi r, which is the base here, multiplied by the height, so it gives you 301.
02:00
Last one for the cube, the surface area is 6 of them, and each one is 4 by 4, that gives you 96.
02:11
Volume wise, it is all three multiplied together to give you 64.
02:19
So the question here asks which cell is the most efficient at bringing in nutrients and getting rid of waste.
02:25
So now we are really looking at the surface area to volume ratios...