00:01
We have a, we want to find the density of a paddle about 0 .46 millimeters in radius.
00:08
We're assuming that it's going to have the density of a neutron.
00:11
And i couldn't find a reliable density of a neutron, but i could find its mass and its weight, or its radius and its weight.
00:21
And so i'm going to calculate the density of a neutron.
00:25
But if you're given one, go ahead and use that one and just pick up to where i start.
00:30
Calculating the density of the pebble.
00:36
I'll be using the volume of a sphere, which is this equation here.
00:54
And so i'm going to find the volume of the neutron and then find the density of the neutron.
01:02
So first, i'm used to densities and centimeters cube.
01:05
So i'm going to convert this to centimeters.
01:06
So i get, i multiply our radius of the neutron by 100 to get centimeters.
01:30
And then i can plug that to get the volume of our neutron times pi times zero times 10 to the negative 14.
01:44
And this gives me a volume of 2 .39, 2 .14 times 10 to negative 3 .9 centimeters cubed.
01:58
Volume of neutron.
02:06
And so now i can take the mass of that 1 .68 times 10 to the negative 24 grams divided by 2 .14 times 10 to 98 39 centimeters cubed grams.
02:20
And this gives me a density for the neutron at 7 .81 times 10 to 14 grams per centimeters cubed.
02:31
And this is now going to be the density i use.
02:38
But if you're given a slightly different one, go ahead and use that number.
02:40
And so from here on out, just plug in whatever number you need if it's different than this one.
02:46
All right.
02:46
So i'm going to find the volume of the pebble...