This question is missing a massive amount of background info required to answer.
longitudinal vibration is one of the types of free vibration because when you start a bike the particles of every part moves up and down
Vibration is a noun.
Vibration is defined as a mechanical fluctuation from one point to another point. There are mainly two types of vibration involved in vibration analysis: free vibration and forced vibration. Free vibration occurs when an object is turned on, such as a clothes dryer and a lawnmower, and is left to vibrate on its own. Forced vibration happens when an outside object or occurrence vibrates an object. The lawnmower shakes due to an earthquake would be an example of this. Furthermore, vibration monitoring is also another important part of analysis.
When one part of a vibration causes air particles to spread out, they form ararefaction
Most of the vibration, and the sound that is a result of that vibration, is in the tubes of the chime. When they hit each other it causes a vibration at a certain frequency which causes a note to issue from the chime. I've linked a wind chime guide that shows the different parts of a chime, part #5 is where the vibration occurs.
front brakes
When one part of a vibration causes air particles to spread out, they form ararefaction
You don't fix this. It is part of what makes a Harley a Harley. Go buy a Honda if you don't like vibration.
inner ear
The kingpin is part of the trailer, not the truck.
The bucket truck designation relates to being part of another truck. The bucket truck is attached to a carrier truck.
Rarefaction