Vibration frequency response function can be calculated, thereby characterizing the system. This technique is used in the field of experimental modal analysis to determine the vibration characteristics of a structure. The simple mass–spring–damper model is the foundation of vibration analysis, but what about more complex systems? The mass–spring–damper model described above is called a single degree of freedom (SDOF) model since the mass is assumed to only move up and down. In more complex systems, the system must be discretized into more masses that move in more than one direction, adding degrees of freedom. The major concepts of multiple degrees of
Unit of alcohol down) about one unit of alcohol per hour, although this may vary depending on sex, age, weight, health, and many other factors. The number of UK units of alcohol in a drink can be determined by multiplying the volume of the drink (in millilitres) by its percentage ABV, and dividing by 1000. For example, one imperial pint (568 ml) of beer at 4% alcohol by volume (ABV) contains: <br> <br> The formula uses . This results in exactly one unit per percentage point per litre, of any alcoholic beverage. The formula can be simplified for everyday use by expressing the