Quantities and unit

1. FUNDAMENTALFUNDAMENTAL
ANDAND
DERIVED QUANTITIESDERIVED QUANTITIES

2. Objectives of Learning
Students are able to:
•identifier physical quantities in daily life
•collected physical quantities classified to
the fundamental quantities and derived
quantities
•Write out the five fundamental physical
quantities and their units.
•Differentiate fundamental and derived
physical quantities

3. Physical Quantities
What is a Physical Quantities?
A physical quantity is a quantity that can be
measured and expressed in numbers and units.

4. •Derived quantities: Quantities which
are derived from fundamental
quantities.
•Fundamental quantities are physical
quantities that cannot be defined in
term of other physical quantities for
they have their own units.

5. Consider the table below!
blacksharpnessdensitybitter
crysoursweetarea
forceamount of
substance
massbusy
volumespeedhappytemperature
saduglycurrent
intensity
love
fatangrybadtime
luminous
intensity
lengthtallbeautiful

6. Fundamental Quantities
No. Quantities unit
1.Length meter [m]
2.Mass kilogram [kg]
3.Time second [s]
4.Electric current ampere [A]
5.Temperature kelvin [K]
6.Amount of substancemole [mol]
7.Luminous intensitycandela { cd }

7. All other physical quantities can be
derived from these seven fundamental
quantities.
These are called derived quantities.
For examples:

8. •SI derived units
•Other quantities, called derived quantities, are
defined in terms of the seven base quantities via
a system of quantity equations. The SI derived
units for these derived quantities are obtained
from these equations and the seven SI base units.
Examples of such SI derived units are given in
Table 2, where it should be noted that the symbol
1 for quantities of dimension 1 such as mass
fraction is generally omitted.

9. • Unit of length  meter The meter is the length
of the path travelled by light in vacuum during
a time interval of 1/299 792 458 of a second.
•Unit of mass kilogram   The kilogram is the
unit of mass; it is equal to the mass of the
international prototype of the kilogram.
• Unit of time second The second is the
duration of 9 192 631 770 periods of the
radiation corresponding to the transition
between the two hyperfine levels of the ground
state of the cesium 133 atom.

10. • Unit of electric current  is ampere The ampere
is that constant current which, if maintained in
two straight parallel conductors of infinite length,
of negligible circular cross-section, and placed 1
meter apart in vacuum, would produce between
these conductors a force equal to 2 x 10-7
newton per meter of length.
• Unit of  temperature is kelvin .The kelvin, unit
of thermodynamic temperature, is the fraction
1/273.16 of the thermodynamic temperature of
the triple point of water.

11. •Unit of amount of substances is mole. The mole
is the amount of substance of a system which
contains as many elementary entities as there
are atoms in 0.012 kilogram of carbon 12; its
symbol is "mol."
•2. When the mole is used, the elementary
entities must be specified and may be atoms,
molecules, ions, electrons, other particles, or
specified groups of such particles.

12. •Unit of luminous intensity is candela The
candela is the luminous intensity, in a given
direction, of a source that emits
monochromatic radiation of frequency 540 x
1012 hertz and that has a radiant intensity in
that direction of 1/683 watt per steradian.