Measurements and Experimentation

Flashcards from Measurements and Experimentation Lecture Notes

What is measurement?

The process of comparison of a given physical quantity with a known standard quantity of the same nature.

What is a unit?

The standard quantity of constant magnitude used to measure the magnitudes of other quantities of the same nature.

List four properties that a chosen unit should have.

Convenient size, defined without ambiguity, reproducible, value should not change with space and time.

What are the two kinds of units?

Fundamental or basic units and derived units.

Give three examples of fundamental units.

Units of mass, length, and time.

What are derived units?

Units that depend on fundamental units or can be expressed in terms of fundamental units.

Give three examples of derived units.

Units of area, volume, and speed.

What are the fundamental quantities in mechanics?

Length, mass, and time.

What are the units of length, mass, and time in the C.G.S. system?

Centimetre (cm), gram (g), and second (s), respectively.

What are the units of length, mass, and time in the F.P.S. system?

Foot (ft), pound (lb), and second (s), respectively.

What are the units of length, mass, and time in the M.K.S. system?

Metre (m), kilogram (kg), and second (s), respectively.

What is the S.I. system?

Systeme Internationale d'Unites, an enlarged and modified version of the metric system.

List seven fundamental quantities in the S.I. system.

Length, mass, time, temperature, luminous intensity, electric current, amount of substance.

Name two complementary fundamental units.

Angle (radian) and solid angle (steradian).

What is the symbol and meaning of the prefix 'kilo'?

Symbol: k, Meaning: 10^3

What is the symbol and meaning of the prefix 'micro'?

Symbol: μ, Meaning: 10^-6

What is the S.I. unit of length?

Meter (m)

Define the meter based on the 1983 redefinition.

The distance traveled by light in 1/299,792,458 of a second in a vacuum.

Name four sub-units of the meter.

Centimeter (cm), millimeter (mm), micron (μ), and nanometer (nm).

What is the relationship between a centimeter and a meter?

1 cm = 10^-2 m

What is the relationship between a millimeter and a meter?

1 mm = 10^-3 m

What is the relationship between a micron and a meter?

1 micron = 10^-6 meter

What is the relationship between a nanometer and a meter?

1 nm = 10^-9 m

Name the multiple unit of meter mentioned in the notes.

Kilometer (km)

What is the relationship between a kilometer and a meter?

1 km = 1000 m (or 10^3 m)

Name three non-metric units of length used for measuring distances between heavenly bodies.

Astronomical unit (A.U.), light year (ly), and parsec.

Define one astronomical unit (A.U.).

Equal to the mean distance between the Earth and the Sun i.e., 1 A.U. = 1.496 x 10^11 metre

Define a light year (ly).

The distance traveled by light in vacuum in one year, i.e., 1 light year = 9.46 x 10^15 m

What is an Angstrom (Å)?

10^-10th part of a metre

What is a fermi (f)?

10^-15th part of a metre

What is the S.I. unit of mass?

Kilogram (kg)

How was one kilogram defined in 1889?

The mass of a cylindrical piece of platinum-iridium alloy kept at the International Bureau of Weights and Measures at Sevres near Paris.

Name two sub-units of the kilogram.

Gram (g) and milligram (mg).

What is the relationship between a gram and a kilogram?

1 g = 10^-3 kg

What is the relationship between a milligram and a kilogram?

1 mg = 10^-6 kg

Name two common multiple units of the kilogram used in daily life.

Quintal and metric tonne.

What is the relationship between a quintal and a kilogram?

1 quintal = 100 kg

What is the relationship between a metric tonne and a kilogram?

1 metric tonne = 1000 kg

What is the atomic mass unit (a.m.u) or unified atomic mass unit (u) used for?

Expressing the mass of atomic particles such as proton, neutron and electron

What is the S.I. unit of time?

Second (s)

Define a second.

The time interval of 9,192,631,770 vibrations of radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium - 133 atom.

Name four units of time bigger than a second.

Minute, hour, day, and month.

How many seconds are there in a minute?

60 s

How many seconds are there in an hour?

3600 s

How many seconds are there in a day?

86400 s

What defines a leap year?

The month of February has 29 days.

What is the duration of a decade?

10 years

What is the duration of a century?

100 years

What is the S.I. unit of area?

m^2

What is the S.I. unit of volume?

m^3