00:01
Hi there, so for this problem, the first problem in here is about moment of inertia of the wagon wheel.
00:13
So the first thing that we have for this is the radius for this that is 0 .3 meters.
00:21
The mass of the rim, it is 1 .40 kilograms.
00:30
Now, each spoke is a slender rod lying along the diameter.
00:35
The length for all for them will be 0 .3 meters.
00:41
The mass of one spoke, same about the last ms, it is 0 .280, and the number of spouts, it is 8.
00:55
Now, let's calculate the moment of inertia of the rim.
00:59
So for the moment of the dimension of the ring, that will be the mass of the rim times its radius to the square.
01:05
So now we substitute the values, 1 .0.
01:08
40 times 0 .3 to the square.
01:12
So this will give us about 0 .126 in units of kilograms times meters square.
01:21
Now the moment of inertia of this boats, each spoke is a thing rot rotating about its center.
01:31
So the moment of inertia of one spoke about the center is one divided by 3 times the moment of one spoke, this mass of one spoke times its length to the square.
01:43
So that will be 1 divided by 3 times 0 .28 times 0 .3 to the square.
01:51
So this will give us a value of 0 .0084 kilograms times give it meters, a meters square.
02:02
Sorry.
02:04
Now, since for the total is boats in here, we have 8, so we need to multiply that value by 8.
02:12
So that will be 0 .0672 kilograms times meters square.
02:19
So the total for this will be the sum of the 0 .126 for the ring plus 0 .6272.
02:30
So this will give us 0 .1932 in units of kilograms times meters square.
02:38
And that will be the solution for problem one.
02:42
Now for problem two, we are talking about rotational kinetic energy of the airplane propeller.
02:51
The length of the propeller for this, it is given, that is 2 .08 meters.
02:57
So then the radius is half of this value, that is 1 .04 meters.
03:01
The mass of the propeller also given, that is 117 kilograms, the rotational speed for this will be 2 ,400 revolutions per minute...