Physics - Measurements

Measurement

The art of comparing unknown values to standard, or the accepted values for a particular quantity.

Units

Physical variables can be used to describe physical phenomena. The standards in which the physical quantities are expressed are called what?

1960

In what year was the International System if Units was established?

General conference on Weights and Measures.

Who adopted the name for the SI units?

Physical Quantities

These are property of an object that can be measured or calculated from other measurements.

Kilogram

The SI unit for mass. It is defined by an international prototype kilogram of platinum-iridium. It is kept in the International Bureau of Weights and Measure in Sevres, France.

Ampere

The SI unit for electric current. It is the current maintained in two straight wires, placed one meter apart in vacuum which produce a force of 2x10-7 Newton per meter of length.

Second

The SI unit for time. It is associated with the specified transition of Cesium-133 atom, during which 9,192,631,770 cycles of microwave radiation are generated by the atom.

Kelvin

The SI unit for temperature. It's named after physicist William Thomson and is similar intervals in the Celsius scale. Adding 273.15 to the Celsius temperature reading will equal the measure in Kelvin scale.

Mole

The SI unit for amount of substance. It is the amount of substance contained in 0.012 kg of Carbon-12. One of it in a substance contains 6.02 x 1023 particles of atoms.

Meter

The SI unit for length. It is defined as the distance traveled by light in vacuum in 1 over 299,792,458 second.

Candela

The SI unit for luminous intensity. It is the intensity of light produced by a source emitting with a frequency of 340x1012 cycle per second in a direction where the intensity is 1 over 683 Watt per steradian.

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Derived Quantity

Are quantities resulting from combination of any of other quantities.

Area

A0roduct of two (2) measures of length

Volume

Product of three (3) measures of length

Velocity

Ratio between length and time

Acceleration

Ratio between length and the square of time

Force

Product of mass and acceleration

Pressure

Ratio between force and area

Imperial System

It represents an amalgamation of different adopted from several ancient cultures.