00:02
Okay, see we have a 2 meter snake, very skinny, so the volume becomes kind of just along the line.
00:08
So we do the density of this function, i want you to define the mass.
00:11
Well, the mass will equal the density integrated from 0 to 2.
00:17
So 2x minus x squared.
00:20
Since we're working on a line, we just do x -d -x.
00:23
If this were a volume snake, we put a volume there.
00:25
But all we have is just the line.
00:27
Very skinny snake.
00:28
So this is 0 to 2 of 2x squared minus x cubed.
00:34
So that is 2 thirds x cubed minus 1 4th, x to the 4th, evaluated from 0 to 2.
00:47
So this is a nice metric here, 2 times 2 cubed over 3 minus 2 to the 4th over 4, which is really both of these are 2 to the 4th.
00:59
2 to the 4th times 1 3rd minus 1 4th, right? so this is 4 twelfths, and this is 3 twelfths, and that's 16, so it's 16 times 112th, which is 16 over 12, or 4 over 3 kilograms.
01:20
Over here, revolving this around the, this is an exponential decay...