Lenght, Mass, and Time

Length

Yard – In A.D. 1120, yard is measure from the standard length of the kings tip nose to the end of his outreached arm (King Louis XIV).

Meter was originally defined as one ten-millionth of the distance from the equator to the North Pole (1791).

Meter was defined by an atomic standard, in terms of the wavelength of the orange- red light emitted by atoms of Krypton (86Kr) in a glow discharge tube; one meter was defined as 1650763.73 of these wavelengths (1960).

Meter was redefined as the distance traveled by light in vacuum during a time of 1/ 299792458 second.

Mass

The MKS unit of mass is Kilogram. Kilogram (Kg) is defined as the mass of a specific platinum-iridium alloy cylinder kept at the International Bureau of Weights and Measures at Serves, France (1887).

Time

The unit of time was based on a certain fraction of the mean solar day, the average time interval between successive arrivals of the sun at its highest point in the sky (1960).

In 1967, the second/s is redefined as 9192631770 times the period of vibration of radiation from the cesium atom (Period is the time interval needed for one complete vibration).

References:

Beiser, Arthur. (1992). Modern Technical Physics. Singapore: Addison-Wesley Publishing Company

Catchillar, Gerry C., and Malenab, Ryan G. (2003). Fundamental Physics. National Bookstore

Giambattista, A, Richardson, B. and Richardson, R. (2007). College Physics. 2^nd Ed. New York: McGraw-Hill Book Companies, Inc.

Giancoli, D.C. (1998). Physics: Principles with Applications 5^th Ed. London Prentice Hall International, Inc.

Halliday, D., Resnick, R. and Walker, J. (1997). Fundamentals of Physics. 5^th Ed. New York: John Wiley & Sons, Inc.

Hewitt, Paul G. (1997). Conceptual Physics, Addison-Wesley Publishing Company United State of America

Serway, Raymond A., and Faughn, Jerry S., (2003) College Physics., 6^th Ed. Brooks/Cole, Thomson Learning Asian Edition.

Serway, Raymond A., and Jewett Jr., John W., (2004) Physics for Scientist and Engineers with Modern Physics., 6^th Ed. Brooks/Cole, Thomson Learning Asian Edition.

Urone, Paul Peter. (2004) Physics with health science application. Philippines: Golden Gate Printer

Young, H.D. and Freedman, R. A. (2000). Unversity Physics. 10^th Ed., Singapore: Addison-Wesley Publishing Company, Inc.