Definition
Physics is the branch of science that studies matter, energy, space, time and the interactions between them. It seeks to explain natural phenomena through observation, experimentation and mathematical models.
Measurement is the process of comparing a physical quantity with an accepted standard called a unit.
Explanation
Physics aims to describe how the universe works by discovering relationships between measurable quantities.
Unlike opinions or assumptions, physical laws are established through repeated observations and experiments. Every scientific measurement must be expressed as a numerical value together with a unit.
For the measurement shown in Figure 1.1.1:
- 7.6 is the numerical value.
- cm (centimeter) is the unit.
Together, they form a complete physical measurement.
A physical quantity is measured by comparing it with a standard unit.
Without a unit, a numerical value has no physical meaning.
Measurements allow scientists and engineers to communicate results consistently, compare observations and verify experimental findings.
Every branch of physics relies on accurate and reliable measurements.
Key Points
- Physics studies the laws governing nature.
- Measurement is the comparison of a physical quantity with a standard unit.
- Every measurement consists of a numerical value and a unit.
- Measurements provide a common language for science and engineering.