INTRODUCTION TO PHYSICS

• UNITS AND MEASUREMENT
• Physics is a science subject that measures science activities. Like all science it interprets science from law(philosophy) into mathematical relationships.
• The mathematical relationships of nature is measured using quantities. Types of quantities are fundamental and derived quantities. A unit is a standard used in measuring quantities. For instance length is a fundamental quantity but length can be measured in meters.
• FUNDAMENTAL QUANTITIES
• Fundamental quantities are those quantities that cannot be derived from other quantities. Fundamental quantities are the building blocks of all other quantities in physics. Fundamental quantities(at this level) includes mass, length, and time. It also includes temperature, electric current and number of moles.

Fundamental quantity	Unit	Symbol
mass	kilogram	Kg
length	meter	m
time	seconds	s
electric current	ampere	A
temperature	kelvin	K
amount of substance	moles	mol

• Table 1: Examples of fundamental quantities
• DERIVED QUANTITIES
• Derived quantities in physics are those quantities that are derived from other quantities. The are usually obtained when two or more quantities are evaluated. A simple example derived quantity is the area of a rectangle(l x b), or the volume (l x b x h) of a cuboid.
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• Fig 1 : Examples of regular solids cuboid, sphere, cylinder, cube.
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Derived quantity	Derivation	Unit
Area(A)	l x b	m2
Volume(V)	l x b x h	m3
velocity (v)	Displacement / time	ms-1
Density (𝛒)	mass/volume	kg/m3
Force(Newton, N)	Mass x acceleration	kgm/s2
Work(Joules)	Force x distance	kgm2/s2

Table 2: Examples of derived quantities.

• NB: Derived quantities makes up bulk of the physics curriculum.

• Physics can be simplified as the ability to understand how quantities both fundamental & derived changes and causes effect in the world around us.