Video Lesson

Lesson Objective

Dear Learners,

At the end of this section, you should be able to:

• Define physics in different ways
• Describe the different branches of physics.

Brainstorming Question

Name other technological products in your locality that rely on the principle of physics.

Key terms and Concepts

Definition and The Nature of Physics

Think about the fact that our historical heritages such as Harar Jugol, Fasciledes Castle, the Obelisk of Axum and rock-hewn churches of Lalibela buildings have kept their balance and survived for hundreds of years. The working principles of all these rely on physics.

These images show the listed historical heritages( ancient technologies) above such as Harar Jugol, Fasciledes Castle, the Obelisk of Axum and rock-hewn churches of Lalibela buildings

The word physics is thought to have come from the Greek word phusis, meaning nature. Hence, physics is a branch of natural science aimed at describing the fundamental aspects of our universe and dealing with unanimate nature. These include what things are in it, what properties of those things are noticeable, and what processes those things or their properties undergo. In simpler terms, physics attempts to describe the basic mechanisms that make our universe behave the way it does.

For example,

• Physics enables you to understand the working principles of cars, airplanes, space-rockets, refrigerators, radios, televisions, etc as well as many of your daily utensils and tools.
• Physics explains physical phenomena such as the difficulty of walking on a smooth plane, and why an electric fan rotates etc.
•  Physics helps you discover some of the unknown parts of nature and makes you familiar with the modern world.

A person who studies physics is called a physicist.

Branches of Physics

As our technology evolved over the centuries, physics has expanded into many branches. Here are some of the main branches of physics along with a brief explanation of each:

• Mechanics is the branch of physics which deals with the motion of an object without or with the reference of force.
• Acoustics is the branch of physics which deals with the study of sound and its transmission, production, and effects.
• Thermodynamics is the branch of physics which studies thermal energy and the transfer of heat.
• Electromagnetism is the branch of physics which deals with the study of electromagnetic force like electric fields, light, magnetic fields, etc
• Nuclear physics is the branch of physics which deals with the structure, properties and reactions of the nuclei of atoms.
• Astrophysics is a science that employs the methods and principles of physics in the study of astronomical objects and phenomena.
• Optics: Investigates the behavior and properties of light.