One Chapter 1

During the 18^th Century science was called natural philosophy.
Later natural philosophy was divided into
- physical sciences
biological sciences
At the end of the 19^th century, physical science was divided into
- physics
- chemistry
Chemistry - The study of the interaction between different kinds of matter on a molecular scale.
Physics – the study of the relationship between matter and energy.
Physics has been divided into a number of areas:
mechanics, waves, optics, electricity, magnetism, nuclear physics, solid state
- physics, particle physics, plasma physics. etc.
Physics is important in other areas of science,
- physical chemistry
- optical chemistry
- biophysics
- geo and astrophysics
- health physics
Physics involves
- measuring of values
- analysis of measurements
- making statements of relationships in formula form.
- application of laws.

DIMENSIONS AND UNITS

Quantities are expressed in terms of Length, mass and time.
Metric system has been used in science since the 1960’s
Since then the name has become the SI system of measurement.
"The International System of Units"
Standards in the SI system:
The above units are defined units.
derived units – units defined in terms of length, mass and time. (e.g.. the Joule)

The quantity of matter an object contains. (Probably your old definition of mass)
A better definition would be:
kilogram – the mass of a cylinder of platinum-iridium alloy kept near Paris.

The Egyptians originated the first unit of time (The Solar day)
The second was originally defined in terms of the solar day.
Today the second is defined in the following way:
- 9 192 631 770 periods of radiation produced by a specific energy change
- in the cesium 133 atom.
Period - The time it takes to repeat some event.
Frequency – the number of repeats of an event per unit of time.

LENGTH

MASS

Time

T = 1/f

T is period and f is frequency.

October 28, 2013