00:01
The first equation is equal to 0.
00:02
Every time we have an equation in this form, y double prime plus k y is equal to 0, where k is any constant, we have simple harmonic motion.
00:15
For part b, we have the fact that this is equal to cosine.
00:20
We know it's some sort of vibration.
00:22
So let's find the damping constant.
00:25
So first, w is the number multiplying the t.
00:30
Which in this case is two radiance per second.
00:32
This is the angular velocity.
00:34
And then w -n is the value multiplying, the square root of the value multiplying the y.
00:41
This is equal to the square root of 1 .8 squared.
00:45
The squares cancel.
00:47
And this is equal to 1 .8 radiance per second.
00:52
So since these two values, it's the two omegas, the two angular velocities, are very close to each other.
00:58
This is a bearing vibration, beating vibration, sorry.
01:03
Beating vibration is given in as the letter b.
01:07
So for question b, the answer would be b...