1 XL â or EXL, Exploration Licence (United Kingdom), a type of onshore licence issued between the First Onshore Licensing Round (1986) and the Sixth (1992). 2  Xln â Crystalline (minerals). 3  XLPE-Cross-linked Polyethylene. 4  XMAC â Cross-Multipole Array Acoustic log.
When the frequency approaches 120 CPM (2 Hz), occupants perceive the ride as harsh. Consequently, the suspension of the average family sedan will have a natural frequency of about 60 to 90 CPM. A high-performance sports car will have a stiffer suspension with a natural frequency of about 120 to 150 CPM (2 to 2.5 Hz). Originally, human sensitivity to ride frequency was believed to be associated with the natural oscillations of an adult human body during a walking gait.
If your car starts making weird engine noises and they are sounds which you are not accustomed to, it can be confusing. All cars will emit some sort of noise, which is the general nature of a vehicle. It develops what some people refer to as a âpersonality,â and these noises become part of the performance of the car.f your car starts making weird engine noises and they are sounds which you are not accustomed to, it can be confusing. All cars will emit some sort of noise, which is the general nature of a vehicle. It develops what some people refer to as a âpersonality,â and these noises become part of the performance of the car.